1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * make complex ${var%...} constructs support optional
45 * make here documents optional
46 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
50 * builtins mandated by standards we don't support:
51 * [un]alias, command, fc, getopts, times:
52 * command -v CMD: print "/path/to/CMD"
53 * prints "CMD" for builtins
54 * prints "alias ALIAS='EXPANSION'" for aliases
55 * prints nothing and sets $? to 1 if not found
56 * command -V CMD: print "CMD is /path/CMD|a shell builtin|etc"
57 * command [-p] CMD: run CMD, even if a function CMD also exists
58 * (can use this to override standalone shell as well)
59 * -p: use default $PATH
60 * command BLTIN: disables special-ness (e.g. errors do not abort)
61 * getopts: getopt() for shells
62 * times: print getrusage(SELF/CHILDREN).ru_utime/ru_stime
63 * fc -l[nr] [BEG] [END]: list range of commands in history
64 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
65 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
68 * redirection of stdout+stderr: &> and >&
69 * reserved words: function select
70 * advanced test: [[ ]]
71 * process substitution: <(list) and >(list)
74 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
75 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
76 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
78 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
79 * This is exactly equivalent to let "EXPR".
80 * $[EXPR]: synonym for $((EXPR))
81 * indirect expansion: ${!VAR}
82 * substring op on @: ${@:n:m}
85 * Some builtins mandated by standards:
86 * newgrp [GRP]: not a builtin in bash but a suid binary
87 * which spawns a new shell with new group ID
88 * In bash, export builtin is special, its arguments are assignments
89 * and therefore expansion of them should be "one-word" expansion:
90 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
92 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
93 * ls: cannot access i=a: No such file or directory
94 * ls: cannot access b: No such file or directory
95 * Note1: same applies to local builtin.
96 * Note2: bash 3.2.33(1) does this only if export word itself
98 * $ export i=`echo 'aaa bbb'`; echo "$i"
100 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
104 //config: bool "hush (64 kb)"
107 //config: hush is a small shell. It handles the normal flow control
108 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
109 //config: case/esac. Redirections, here documents, $((arithmetic))
110 //config: and functions are supported.
112 //config: It will compile and work on no-mmu systems.
114 //config: It does not handle select, aliases, tilde expansion,
115 //config: &>file and >&file redirection of stdout+stderr.
117 //config:config HUSH_BASH_COMPAT
118 //config: bool "bash-compatible extensions"
120 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
122 //config:config HUSH_BRACE_EXPANSION
123 //config: bool "Brace expansion"
125 //config: depends on HUSH_BASH_COMPAT
127 //config: Enable {abc,def} extension.
129 //config:config HUSH_INTERACTIVE
130 //config: bool "Interactive mode"
132 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
134 //config: Enable interactive mode (prompt and command editing).
135 //config: Without this, hush simply reads and executes commands
136 //config: from stdin just like a shell script from a file.
137 //config: No prompt, no PS1/PS2 magic shell variables.
139 //config:config HUSH_SAVEHISTORY
140 //config: bool "Save command history to .hush_history"
142 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
144 //config:config HUSH_JOB
145 //config: bool "Job control"
147 //config: depends on HUSH_INTERACTIVE
149 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
150 //config: command (not entire shell), fg/bg builtins work. Without this option,
151 //config: "cmd &" still works by simply spawning a process and immediately
152 //config: prompting for next command (or executing next command in a script),
153 //config: but no separate process group is formed.
155 //config:config HUSH_TICK
156 //config: bool "Support process substitution"
158 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
160 //config: Enable `command` and $(command).
162 //config:config HUSH_IF
163 //config: bool "Support if/then/elif/else/fi"
165 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
167 //config:config HUSH_LOOPS
168 //config: bool "Support for, while and until loops"
170 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
172 //config:config HUSH_CASE
173 //config: bool "Support case ... esac statement"
175 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
177 //config: Enable case ... esac statement. +400 bytes.
179 //config:config HUSH_FUNCTIONS
180 //config: bool "Support funcname() { commands; } syntax"
182 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
184 //config: Enable support for shell functions. +800 bytes.
186 //config:config HUSH_LOCAL
187 //config: bool "local builtin"
189 //config: depends on HUSH_FUNCTIONS
191 //config: Enable support for local variables in functions.
193 //config:config HUSH_RANDOM_SUPPORT
194 //config: bool "Pseudorandom generator and $RANDOM variable"
196 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
198 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
199 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
201 //config:config HUSH_MODE_X
202 //config: bool "Support 'hush -x' option and 'set -x' command"
204 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
206 //config: This instructs hush to print commands before execution.
207 //config: Adds ~300 bytes.
209 //config:config HUSH_ECHO
210 //config: bool "echo builtin"
212 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
214 //config:config HUSH_PRINTF
215 //config: bool "printf builtin"
217 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
219 //config:config HUSH_TEST
220 //config: bool "test builtin"
222 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
224 //config:config HUSH_HELP
225 //config: bool "help builtin"
227 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
229 //config:config HUSH_EXPORT
230 //config: bool "export builtin"
232 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
234 //config:config HUSH_EXPORT_N
235 //config: bool "Support 'export -n' option"
237 //config: depends on HUSH_EXPORT
239 //config: export -n unexports variables. It is a bash extension.
241 //config:config HUSH_READONLY
242 //config: bool "readonly builtin"
244 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
246 //config: Enable support for read-only variables.
248 //config:config HUSH_KILL
249 //config: bool "kill builtin (supports kill %jobspec)"
251 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
253 //config:config HUSH_WAIT
254 //config: bool "wait builtin"
256 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
258 //config:config HUSH_TRAP
259 //config: bool "trap builtin"
261 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
263 //config:config HUSH_TYPE
264 //config: bool "type builtin"
266 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
268 //config:config HUSH_READ
269 //config: bool "read builtin"
271 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config:config HUSH_SET
274 //config: bool "set builtin"
276 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
278 //config:config HUSH_UNSET
279 //config: bool "unset builtin"
281 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
283 //config:config HUSH_ULIMIT
284 //config: bool "ulimit builtin"
286 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
288 //config:config HUSH_UMASK
289 //config: bool "umask builtin"
291 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
293 //config:config HUSH_MEMLEAK
294 //config: bool "memleak builtin (debugging)"
296 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
298 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
299 // APPLET_ODDNAME:name main location suid_type help
300 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
301 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
303 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
304 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
305 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
306 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
308 /* -i (interactive) and -s (read stdin) are also accepted,
309 * but currently do nothing, therefore aren't shown in help.
310 * NOMMU-specific options are not meant to be used by users,
311 * therefore we don't show them either.
313 //usage:#define hush_trivial_usage
314 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
315 //usage:#define hush_full_usage "\n\n"
316 //usage: "Unix shell interpreter"
318 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
319 || defined(__APPLE__) \
321 # include <malloc.h> /* for malloc_trim */
324 /* #include <dmalloc.h> */
326 # include <fnmatch.h>
328 #include <sys/utsname.h> /* for setting $HOSTNAME */
330 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
332 #include "shell_common.h"
335 #if ENABLE_HUSH_RANDOM_SUPPORT
338 # define CLEAR_RANDOM_T(rnd) ((void)0)
340 #ifndef F_DUPFD_CLOEXEC
341 # define F_DUPFD_CLOEXEC F_DUPFD
344 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
348 /* So far, all bash compat is controlled by one config option */
349 /* Separate defines document which part of code implements what */
350 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
351 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
352 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
353 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
354 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
358 #define LEAK_HUNTING 0
359 #define BUILD_AS_NOMMU 0
360 /* Enable/disable sanity checks. Ok to enable in production,
361 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
362 * Keeping 1 for now even in released versions.
365 /* Slightly bigger (+200 bytes), but faster hush.
366 * So far it only enables a trick with counting SIGCHLDs and forks,
367 * which allows us to do fewer waitpid's.
368 * (we can detect a case where neither forks were done nor SIGCHLDs happened
369 * and therefore waitpid will return the same result as last time)
371 #define ENABLE_HUSH_FAST 0
372 /* TODO: implement simplified code for users which do not need ${var%...} ops
373 * So far ${var%...} ops are always enabled:
375 #define ENABLE_HUSH_DOLLAR_OPS 1
380 # undef USE_FOR_NOMMU
383 # define USE_FOR_NOMMU(...) __VA_ARGS__
384 # define USE_FOR_MMU(...)
387 #include "NUM_APPLETS.h"
389 /* STANDALONE does not make sense, and won't compile */
390 # undef CONFIG_FEATURE_SH_STANDALONE
391 # undef ENABLE_FEATURE_SH_STANDALONE
392 # undef IF_FEATURE_SH_STANDALONE
393 # undef IF_NOT_FEATURE_SH_STANDALONE
394 # define ENABLE_FEATURE_SH_STANDALONE 0
395 # define IF_FEATURE_SH_STANDALONE(...)
396 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
399 #if !ENABLE_HUSH_INTERACTIVE
400 # undef ENABLE_FEATURE_EDITING
401 # define ENABLE_FEATURE_EDITING 0
402 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
403 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
404 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
405 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
408 /* Do we support ANY keywords? */
409 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
410 # define HAS_KEYWORDS 1
411 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
412 # define IF_HAS_NO_KEYWORDS(...)
414 # define HAS_KEYWORDS 0
415 # define IF_HAS_KEYWORDS(...)
416 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
419 /* If you comment out one of these below, it will be #defined later
420 * to perform debug printfs to stderr: */
421 #define debug_printf(...) do {} while (0)
422 /* Finer-grained debug switches */
423 #define debug_printf_parse(...) do {} while (0)
424 #define debug_print_tree(a, b) do {} while (0)
425 #define debug_printf_exec(...) do {} while (0)
426 #define debug_printf_env(...) do {} while (0)
427 #define debug_printf_jobs(...) do {} while (0)
428 #define debug_printf_expand(...) do {} while (0)
429 #define debug_printf_varexp(...) do {} while (0)
430 #define debug_printf_glob(...) do {} while (0)
431 #define debug_printf_redir(...) do {} while (0)
432 #define debug_printf_list(...) do {} while (0)
433 #define debug_printf_subst(...) do {} while (0)
434 #define debug_printf_clean(...) do {} while (0)
436 #define ERR_PTR ((void*)(long)1)
438 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
440 #define _SPECIAL_VARS_STR "_*@$!?#"
441 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
442 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
443 #if BASH_PATTERN_SUBST
444 /* Support / and // replace ops */
445 /* Note that // is stored as \ in "encoded" string representation */
446 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
447 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
448 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
450 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
451 # define VAR_SUBST_OPS "%#:-=+?"
452 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
455 #define SPECIAL_VAR_SYMBOL 3
459 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
461 /* This supports saving pointers malloced in vfork child,
462 * to be freed in the parent.
465 typedef struct nommu_save_t {
467 struct variable *old_vars;
469 char **argv_from_re_execing;
482 #if ENABLE_HUSH_LOOPS
489 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
494 /* three pseudo-keywords support contrived "case" syntax: */
495 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
496 RES_MATCH , /* "word)" */
497 RES_CASE_BODY, /* "this command is inside CASE" */
504 typedef struct o_string {
506 int length; /* position where data is appended */
509 /* At least some part of the string was inside '' or "",
510 * possibly empty one: word"", wo''rd etc. */
511 smallint has_quoted_part;
512 smallint has_empty_slot;
513 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
516 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
518 /* Protect newly added chars against globbing
519 * by prepending \ to *, ?, [, \ */
520 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
523 MAYBE_ASSIGNMENT = 0,
524 DEFINITELY_ASSIGNMENT = 1,
526 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
529 /* Used for initialization: o_string foo = NULL_O_STRING; */
530 #define NULL_O_STRING { NULL }
532 #ifndef debug_printf_parse
533 static const char *const assignment_flag[] = {
535 "DEFINITELY_ASSIGNMENT",
541 typedef struct in_str {
543 #if ENABLE_HUSH_INTERACTIVE
544 smallint promptmode; /* 0: PS1, 1: PS2 */
551 /* The descrip member of this structure is only used to make
552 * debugging output pretty */
553 static const struct {
555 signed char default_fd;
558 { O_RDONLY, 0, "<" },
559 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
560 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
561 { O_CREAT|O_RDWR, 1, "<>" },
562 { O_RDONLY, 0, "<<" },
563 /* Should not be needed. Bogus default_fd helps in debugging */
564 /* { O_RDONLY, 77, "<<" }, */
567 struct redir_struct {
568 struct redir_struct *next;
569 char *rd_filename; /* filename */
570 int rd_fd; /* fd to redirect */
571 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
573 smallint rd_type; /* (enum redir_type) */
574 /* note: for heredocs, rd_filename contains heredoc delimiter,
575 * and subsequently heredoc itself; and rd_dup is a bitmask:
576 * bit 0: do we need to trim leading tabs?
577 * bit 1: is heredoc quoted (<<'delim' syntax) ?
580 typedef enum redir_type {
582 REDIRECT_OVERWRITE = 1,
585 REDIRECT_HEREDOC = 4,
586 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
589 REDIRFD_SYNTAX_ERR = -2,
590 REDIRFD_TO_FILE = -1,
591 /* otherwise, rd_fd is redirected to rd_dup */
593 HEREDOC_SKIPTABS = 1,
599 pid_t pid; /* 0 if exited */
600 int assignment_cnt; /* how many argv[i] are assignments? */
601 smallint cmd_type; /* CMD_xxx */
603 #define CMD_SUBSHELL 1
605 /* used for "[[ EXPR ]]" */
606 # define CMD_SINGLEWORD_NOGLOB 2
608 #if ENABLE_HUSH_FUNCTIONS
609 # define CMD_FUNCDEF 3
612 smalluint cmd_exitcode;
613 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
616 char *group_as_string;
618 #if ENABLE_HUSH_FUNCTIONS
619 struct function *child_func;
620 /* This field is used to prevent a bug here:
621 * while...do f1() {a;}; f1; f1() {b;}; f1; done
622 * When we execute "f1() {a;}" cmd, we create new function and clear
623 * cmd->group, cmd->group_as_string, cmd->argv[0].
624 * When we execute "f1() {b;}", we notice that f1 exists,
625 * and that its "parent cmd" struct is still "alive",
626 * we put those fields back into cmd->xxx
627 * (struct function has ->parent_cmd ptr to facilitate that).
628 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
629 * Without this trick, loop would execute a;b;b;b;...
630 * instead of correct sequence a;b;a;b;...
631 * When command is freed, it severs the link
632 * (sets ->child_func->parent_cmd to NULL).
635 char **argv; /* command name and arguments */
636 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
637 * and on execution these are substituted with their values.
638 * Substitution can make _several_ words out of one argv[n]!
639 * Example: argv[0]=='.^C*^C.' here: echo .$*.
640 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
642 struct redir_struct *redirects; /* I/O redirections */
644 /* Is there anything in this command at all? */
645 #define IS_NULL_CMD(cmd) \
646 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
650 int num_cmds; /* total number of commands in pipe */
651 int alive_cmds; /* number of commands running (not exited) */
652 int stopped_cmds; /* number of commands alive, but stopped */
654 unsigned jobid; /* job number */
655 pid_t pgrp; /* process group ID for the job */
656 char *cmdtext; /* name of job */
658 struct command *cmds; /* array of commands in pipe */
659 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
660 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
661 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
663 typedef enum pipe_style {
669 /* Is there anything in this pipe at all? */
670 #define IS_NULL_PIPE(pi) \
671 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
673 /* This holds pointers to the various results of parsing */
674 struct parse_context {
675 /* linked list of pipes */
676 struct pipe *list_head;
677 /* last pipe (being constructed right now) */
679 /* last command in pipe (being constructed right now) */
680 struct command *command;
681 /* last redirect in command->redirects list */
682 struct redir_struct *pending_redirect;
688 smallint ctx_inverted; /* "! cmd | cmd" */
690 smallint ctx_dsemicolon; /* ";;" seen */
692 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
694 /* group we are enclosed in:
695 * example: "if pipe1; pipe2; then pipe3; fi"
696 * when we see "if" or "then", we malloc and copy current context,
697 * and make ->stack point to it. then we parse pipeN.
698 * when closing "then" / fi" / whatever is found,
699 * we move list_head into ->stack->command->group,
700 * copy ->stack into current context, and delete ->stack.
701 * (parsing of { list } and ( list ) doesn't use this method)
703 struct parse_context *stack;
707 /* On program start, environ points to initial environment.
708 * putenv adds new pointers into it, unsetenv removes them.
709 * Neither of these (de)allocates the strings.
710 * setenv allocates new strings in malloc space and does putenv,
711 * and thus setenv is unusable (leaky) for shell's purposes */
712 #define setenv(...) setenv_is_leaky_dont_use()
714 struct variable *next;
715 char *varstr; /* points to "name=" portion */
716 #if ENABLE_HUSH_LOCAL
717 unsigned func_nest_level;
719 int max_len; /* if > 0, name is part of initial env; else name is malloced */
720 smallint flg_export; /* putenv should be done on this var */
721 smallint flg_read_only;
729 #if ENABLE_HUSH_FUNCTIONS
731 struct function *next;
733 struct command *parent_cmd;
736 char *body_as_string;
742 /* set -/+o OPT support. (TODO: make it optional)
743 * bash supports the following opts:
754 * interactive-comments on
772 static const char o_opt_strings[] ALIGN1 =
776 #if ENABLE_HUSH_MODE_X
784 #if ENABLE_HUSH_MODE_X
792 struct FILE_list *next;
798 /* "Globals" within this file */
799 /* Sorted roughly by size (smaller offsets == smaller code) */
801 /* interactive_fd != 0 means we are an interactive shell.
802 * If we are, then saved_tty_pgrp can also be != 0, meaning
803 * that controlling tty is available. With saved_tty_pgrp == 0,
804 * job control still works, but terminal signals
805 * (^C, ^Z, ^Y, ^\) won't work at all, and background
806 * process groups can only be created with "cmd &".
807 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
808 * to give tty to the foreground process group,
809 * and will take it back when the group is stopped (^Z)
812 #if ENABLE_HUSH_INTERACTIVE
813 /* 'interactive_fd' is a fd# open to ctty, if we have one
814 * _AND_ if we decided to act interactively */
818 # define G_interactive_fd (G.interactive_fd)
820 # define G_interactive_fd 0
822 #if ENABLE_FEATURE_EDITING
823 line_input_t *line_input_state;
828 #if ENABLE_HUSH_RANDOM_SUPPORT
834 pid_t saved_tty_pgrp;
835 struct pipe *job_list;
836 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
838 # define G_saved_tty_pgrp 0
840 /* How deeply are we in context where "set -e" is ignored */
842 /* "set -e" rules (do we follow them correctly?):
843 * Exit if pipe, list, or compound command exits with a non-zero status.
844 * Shell does not exit if failed command is part of condition in
845 * if/while, part of && or || list except the last command, any command
846 * in a pipe but the last, or if the command's return value is being
847 * inverted with !. If a compound command other than a subshell returns a
848 * non-zero status because a command failed while -e was being ignored, the
849 * shell does not exit. A trap on ERR, if set, is executed before the shell
850 * exits [ERR is a bashism].
852 * If a compound command or function executes in a context where -e is
853 * ignored, none of the commands executed within are affected by the -e
854 * setting. If a compound command or function sets -e while executing in a
855 * context where -e is ignored, that setting does not have any effect until
856 * the compound command or the command containing the function call completes.
859 char o_opt[NUM_OPT_O];
860 #if ENABLE_HUSH_MODE_X
861 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
865 smallint flag_SIGINT;
866 #if ENABLE_HUSH_LOOPS
867 smallint flag_break_continue;
869 #if ENABLE_HUSH_FUNCTIONS
870 /* 0: outside of a function (or sourced file)
871 * -1: inside of a function, ok to use return builtin
872 * 1: return is invoked, skip all till end of func
874 smallint flag_return_in_progress;
875 # define G_flag_return_in_progress (G.flag_return_in_progress)
877 # define G_flag_return_in_progress 0
879 smallint exiting; /* used to prevent EXIT trap recursion */
880 /* These four support $?, $#, and $1 */
881 smalluint last_exitcode;
882 smalluint last_bg_pid_exitcode;
884 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
885 smalluint global_args_malloced;
886 # define G_global_args_malloced (G.global_args_malloced)
888 # define G_global_args_malloced 0
890 /* how many non-NULL argv's we have. NB: $# + 1 */
894 char *argv0_for_re_execing;
896 #if ENABLE_HUSH_LOOPS
897 unsigned depth_break_continue;
898 unsigned depth_of_loop;
902 struct variable *top_var;
903 char **expanded_assignments;
904 #if ENABLE_HUSH_FUNCTIONS
905 struct function *top_func;
906 # if ENABLE_HUSH_LOCAL
907 struct variable **shadowed_vars_pp;
908 unsigned func_nest_level;
911 /* Signal and trap handling */
913 unsigned count_SIGCHLD;
914 unsigned handled_SIGCHLD;
915 smallint we_have_children;
917 struct FILE_list *FILE_list;
918 /* Which signals have non-DFL handler (even with no traps set)?
919 * Set at the start to:
920 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
921 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
922 * The rest is cleared right before execv syscalls.
923 * Other than these two times, never modified.
925 unsigned special_sig_mask;
927 unsigned fatal_sig_mask;
928 # define G_fatal_sig_mask (G.fatal_sig_mask)
930 # define G_fatal_sig_mask 0
933 char **traps; /* char *traps[NSIG] */
934 # define G_traps G.traps
936 # define G_traps ((char**)NULL)
938 sigset_t pending_set;
939 #if ENABLE_HUSH_MEMLEAK
940 unsigned long memleak_value;
946 #if ENABLE_FEATURE_EDITING
947 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
950 #define G (*ptr_to_globals)
951 /* Not #defining name to G.name - this quickly gets unwieldy
952 * (too many defines). Also, I actually prefer to see when a variable
953 * is global, thus "G." prefix is a useful hint */
954 #define INIT_G() do { \
955 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
956 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
957 sigfillset(&G.sa.sa_mask); \
958 G.sa.sa_flags = SA_RESTART; \
962 /* Function prototypes for builtins */
963 static int builtin_cd(char **argv) FAST_FUNC;
965 static int builtin_echo(char **argv) FAST_FUNC;
967 static int builtin_eval(char **argv) FAST_FUNC;
968 static int builtin_exec(char **argv) FAST_FUNC;
969 static int builtin_exit(char **argv) FAST_FUNC;
970 #if ENABLE_HUSH_EXPORT
971 static int builtin_export(char **argv) FAST_FUNC;
973 #if ENABLE_HUSH_READONLY
974 static int builtin_readonly(char **argv) FAST_FUNC;
977 static int builtin_fg_bg(char **argv) FAST_FUNC;
978 static int builtin_jobs(char **argv) FAST_FUNC;
981 static int builtin_help(char **argv) FAST_FUNC;
983 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
984 static int builtin_history(char **argv) FAST_FUNC;
986 #if ENABLE_HUSH_LOCAL
987 static int builtin_local(char **argv) FAST_FUNC;
989 #if ENABLE_HUSH_MEMLEAK
990 static int builtin_memleak(char **argv) FAST_FUNC;
992 #if ENABLE_HUSH_PRINTF
993 static int builtin_printf(char **argv) FAST_FUNC;
995 static int builtin_pwd(char **argv) FAST_FUNC;
997 static int builtin_read(char **argv) FAST_FUNC;
1000 static int builtin_set(char **argv) FAST_FUNC;
1002 static int builtin_shift(char **argv) FAST_FUNC;
1003 static int builtin_source(char **argv) FAST_FUNC;
1004 #if ENABLE_HUSH_TEST || BASH_TEST2
1005 static int builtin_test(char **argv) FAST_FUNC;
1007 #if ENABLE_HUSH_TRAP
1008 static int builtin_trap(char **argv) FAST_FUNC;
1010 #if ENABLE_HUSH_TYPE
1011 static int builtin_type(char **argv) FAST_FUNC;
1013 static int builtin_true(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_UMASK
1015 static int builtin_umask(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_UNSET
1018 static int builtin_unset(char **argv) FAST_FUNC;
1020 #if ENABLE_HUSH_KILL
1021 static int builtin_kill(char **argv) FAST_FUNC;
1023 #if ENABLE_HUSH_WAIT
1024 static int builtin_wait(char **argv) FAST_FUNC;
1026 #if ENABLE_HUSH_LOOPS
1027 static int builtin_break(char **argv) FAST_FUNC;
1028 static int builtin_continue(char **argv) FAST_FUNC;
1030 #if ENABLE_HUSH_FUNCTIONS
1031 static int builtin_return(char **argv) FAST_FUNC;
1034 /* Table of built-in functions. They can be forked or not, depending on
1035 * context: within pipes, they fork. As simple commands, they do not.
1036 * When used in non-forking context, they can change global variables
1037 * in the parent shell process. If forked, of course they cannot.
1038 * For example, 'unset foo | whatever' will parse and run, but foo will
1039 * still be set at the end. */
1040 struct built_in_command {
1042 int (*b_function)(char **argv) FAST_FUNC;
1043 #if ENABLE_HUSH_HELP
1044 const char *b_descr;
1045 # define BLTIN(cmd, func, help) { cmd, func, help }
1047 # define BLTIN(cmd, func, help) { cmd, func }
1051 static const struct built_in_command bltins1[] = {
1052 BLTIN("." , builtin_source , "Run commands in file"),
1053 BLTIN(":" , builtin_true , NULL),
1055 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1057 #if ENABLE_HUSH_LOOPS
1058 BLTIN("break" , builtin_break , "Exit loop"),
1060 BLTIN("cd" , builtin_cd , "Change directory"),
1061 #if ENABLE_HUSH_LOOPS
1062 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1064 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1065 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1066 BLTIN("exit" , builtin_exit , NULL),
1067 #if ENABLE_HUSH_EXPORT
1068 BLTIN("export" , builtin_export , "Set environment variables"),
1071 BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"),
1073 #if ENABLE_HUSH_HELP
1074 BLTIN("help" , builtin_help , NULL),
1076 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1077 BLTIN("history" , builtin_history , "Show history"),
1080 BLTIN("jobs" , builtin_jobs , "List jobs"),
1082 #if ENABLE_HUSH_KILL
1083 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1085 #if ENABLE_HUSH_LOCAL
1086 BLTIN("local" , builtin_local , "Set local variables"),
1088 #if ENABLE_HUSH_MEMLEAK
1089 BLTIN("memleak" , builtin_memleak , NULL),
1091 #if ENABLE_HUSH_READ
1092 BLTIN("read" , builtin_read , "Input into variable"),
1094 #if ENABLE_HUSH_READONLY
1095 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1097 #if ENABLE_HUSH_FUNCTIONS
1098 BLTIN("return" , builtin_return , "Return from function"),
1101 BLTIN("set" , builtin_set , "Set positional parameters"),
1103 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1105 BLTIN("source" , builtin_source , NULL),
1107 #if ENABLE_HUSH_TRAP
1108 BLTIN("trap" , builtin_trap , "Trap signals"),
1110 BLTIN("true" , builtin_true , NULL),
1111 #if ENABLE_HUSH_TYPE
1112 BLTIN("type" , builtin_type , "Show command type"),
1114 #if ENABLE_HUSH_ULIMIT
1115 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1117 #if ENABLE_HUSH_UMASK
1118 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1120 #if ENABLE_HUSH_UNSET
1121 BLTIN("unset" , builtin_unset , "Unset variables"),
1123 #if ENABLE_HUSH_WAIT
1124 BLTIN("wait" , builtin_wait , "Wait for process to finish"),
1127 /* These builtins won't be used if we are on NOMMU and need to re-exec
1128 * (it's cheaper to run an external program in this case):
1130 static const struct built_in_command bltins2[] = {
1131 #if ENABLE_HUSH_TEST
1132 BLTIN("[" , builtin_test , NULL),
1135 BLTIN("[[" , builtin_test , NULL),
1137 #if ENABLE_HUSH_ECHO
1138 BLTIN("echo" , builtin_echo , NULL),
1140 #if ENABLE_HUSH_PRINTF
1141 BLTIN("printf" , builtin_printf , NULL),
1143 BLTIN("pwd" , builtin_pwd , NULL),
1144 #if ENABLE_HUSH_TEST
1145 BLTIN("test" , builtin_test , NULL),
1153 /* prevent disasters with G.debug_indent < 0 */
1154 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1155 # define debug_enter() (G.debug_indent++)
1156 # define debug_leave() (G.debug_indent--)
1158 # define indent() ((void)0)
1159 # define debug_enter() ((void)0)
1160 # define debug_leave() ((void)0)
1163 #ifndef debug_printf
1164 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 #ifndef debug_printf_parse
1168 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1171 #ifndef debug_printf_exec
1172 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1175 #ifndef debug_printf_env
1176 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1179 #ifndef debug_printf_jobs
1180 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1181 # define DEBUG_JOBS 1
1183 # define DEBUG_JOBS 0
1186 #ifndef debug_printf_expand
1187 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1188 # define DEBUG_EXPAND 1
1190 # define DEBUG_EXPAND 0
1193 #ifndef debug_printf_varexp
1194 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1197 #ifndef debug_printf_glob
1198 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1199 # define DEBUG_GLOB 1
1201 # define DEBUG_GLOB 0
1204 #ifndef debug_printf_redir
1205 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1208 #ifndef debug_printf_list
1209 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1212 #ifndef debug_printf_subst
1213 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1216 #ifndef debug_printf_clean
1217 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1218 # define DEBUG_CLEAN 1
1220 # define DEBUG_CLEAN 0
1224 static void debug_print_strings(const char *prefix, char **vv)
1227 fdprintf(2, "%s:\n", prefix);
1229 fdprintf(2, " '%s'\n", *vv++);
1232 # define debug_print_strings(prefix, vv) ((void)0)
1236 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1239 static void *xxmalloc(int lineno, size_t size)
1241 void *ptr = xmalloc((size + 0xff) & ~0xff);
1242 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1245 static void *xxrealloc(int lineno, void *ptr, size_t size)
1247 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1248 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1251 static char *xxstrdup(int lineno, const char *str)
1253 char *ptr = xstrdup(str);
1254 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1257 static void xxfree(void *ptr)
1259 fdprintf(2, "free %p\n", ptr);
1262 # define xmalloc(s) xxmalloc(__LINE__, s)
1263 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1264 # define xstrdup(s) xxstrdup(__LINE__, s)
1265 # define free(p) xxfree(p)
1269 /* Syntax and runtime errors. They always abort scripts.
1270 * In interactive use they usually discard unparsed and/or unexecuted commands
1271 * and return to the prompt.
1272 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1275 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1276 # define syntax_error(lineno, msg) syntax_error(msg)
1277 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1278 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1279 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1280 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1283 static void die_if_script(unsigned lineno, const char *fmt, ...)
1288 bb_error_msg("hush.c:%u", lineno);
1291 bb_verror_msg(fmt, p, NULL);
1293 if (!G_interactive_fd)
1297 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1300 bb_error_msg("syntax error: %s", msg);
1302 bb_error_msg("syntax error");
1305 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1307 bb_error_msg("syntax error at '%s'", msg);
1310 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1312 bb_error_msg("syntax error: unterminated %s", s);
1315 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1317 char msg[2] = { ch, '\0' };
1318 syntax_error_unterm_str(lineno, msg);
1321 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1327 bb_error_msg("hush.c:%u", lineno);
1329 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1333 # undef die_if_script
1334 # undef syntax_error
1335 # undef syntax_error_at
1336 # undef syntax_error_unterm_ch
1337 # undef syntax_error_unterm_str
1338 # undef syntax_error_unexpected_ch
1340 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1341 # define syntax_error(msg) syntax_error(__LINE__, msg)
1342 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1343 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1344 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1345 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1349 #if ENABLE_HUSH_INTERACTIVE
1350 static void cmdedit_update_prompt(void);
1352 # define cmdedit_update_prompt() ((void)0)
1356 /* Utility functions
1358 /* Replace each \x with x in place, return ptr past NUL. */
1359 static char *unbackslash(char *src)
1361 char *dst = src = strchrnul(src, '\\');
1365 if ((*dst++ = *src++) == '\0')
1371 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1392 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1393 v[count1 + count2] = NULL;
1396 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1400 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1402 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1403 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1406 #define add_strings_to_strings(strings, add, need_to_dup) \
1407 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1410 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1411 static char **add_string_to_strings(char **strings, char *add)
1416 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1419 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1421 char **ptr = add_string_to_strings(strings, add);
1422 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1425 #define add_string_to_strings(strings, add) \
1426 xx_add_string_to_strings(__LINE__, strings, add)
1429 static void free_strings(char **strings)
1443 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1447 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1457 static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
1461 newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
1467 /* fd was not open? */
1472 if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
1473 fcntl(newfd, F_SETFD, FD_CLOEXEC);
1479 /* Manipulating the list of open FILEs */
1480 static FILE *remember_FILE(FILE *fp)
1483 struct FILE_list *n = xmalloc(sizeof(*n));
1484 n->next = G.FILE_list;
1488 close_on_exec_on(n->fd);
1492 static void fclose_and_forget(FILE *fp)
1494 struct FILE_list **pp = &G.FILE_list;
1496 struct FILE_list *cur = *pp;
1497 if (cur->fp == fp) {
1506 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1508 struct FILE_list *fl = G.FILE_list;
1511 /* We use it only on script files, they are all CLOEXEC */
1512 fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
1513 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1520 static void restore_redirected_FILEs(void)
1522 struct FILE_list *fl = G.FILE_list;
1524 int should_be = fileno(fl->fp);
1525 if (fl->fd != should_be) {
1526 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1527 xmove_fd(fl->fd, should_be);
1533 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1534 static void close_all_FILE_list(void)
1536 struct FILE_list *fl = G.FILE_list;
1538 /* fclose would also free FILE object.
1539 * It is disastrous if we share memory with a vforked parent.
1540 * I'm not sure we never come here after vfork.
1541 * Therefore just close fd, nothing more.
1543 /*fclose(fl->fp); - unsafe */
1549 static int fd_in_FILEs(int fd)
1551 struct FILE_list *fl = G.FILE_list;
1561 /* Helpers for setting new $n and restoring them back
1563 typedef struct save_arg_t {
1567 IF_HUSH_SET(smallint sv_g_malloced;)
1570 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1572 sv->sv_argv0 = argv[0];
1573 sv->sv_g_argv = G.global_argv;
1574 sv->sv_g_argc = G.global_argc;
1575 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1577 argv[0] = G.global_argv[0]; /* retain $0 */
1578 G.global_argv = argv;
1579 IF_HUSH_SET(G.global_args_malloced = 0;)
1581 G.global_argc = 1 + string_array_len(argv + 1);
1584 static void restore_G_args(save_arg_t *sv, char **argv)
1587 if (G.global_args_malloced) {
1588 /* someone ran "set -- arg1 arg2 ...", undo */
1589 char **pp = G.global_argv;
1590 while (*++pp) /* note: does not free $0 */
1592 free(G.global_argv);
1595 argv[0] = sv->sv_argv0;
1596 G.global_argv = sv->sv_g_argv;
1597 G.global_argc = sv->sv_g_argc;
1598 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1602 /* Basic theory of signal handling in shell
1603 * ========================================
1604 * This does not describe what hush does, rather, it is current understanding
1605 * what it _should_ do. If it doesn't, it's a bug.
1606 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1608 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1609 * is finished or backgrounded. It is the same in interactive and
1610 * non-interactive shells, and is the same regardless of whether
1611 * a user trap handler is installed or a shell special one is in effect.
1612 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1613 * backgrounds (i.e. stops) or kills all members of currently running
1616 * Wait builtin is interruptible by signals for which user trap is set
1617 * or by SIGINT in interactive shell.
1619 * Trap handlers will execute even within trap handlers. (right?)
1621 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1622 * except for handlers set to '' (empty string).
1624 * If job control is off, backgrounded commands ("cmd &")
1625 * have SIGINT, SIGQUIT set to SIG_IGN.
1627 * Commands which are run in command substitution ("`cmd`")
1628 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1630 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1631 * by the shell from its parent.
1633 * Signals which differ from SIG_DFL action
1634 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1637 * SIGTERM (interactive): ignore
1638 * SIGHUP (interactive):
1639 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1640 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1641 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1642 * that all pipe members are stopped. Try this in bash:
1643 * while :; do :; done - ^Z does not background it
1644 * (while :; do :; done) - ^Z backgrounds it
1645 * SIGINT (interactive): wait for last pipe, ignore the rest
1646 * of the command line, show prompt. NB: ^C does not send SIGINT
1647 * to interactive shell while shell is waiting for a pipe,
1648 * since shell is bg'ed (is not in foreground process group).
1649 * Example 1: this waits 5 sec, but does not execute ls:
1650 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1651 * Example 2: this does not wait and does not execute ls:
1652 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1653 * Example 3: this does not wait 5 sec, but executes ls:
1654 * "sleep 5; ls -l" + press ^C
1655 * Example 4: this does not wait and does not execute ls:
1656 * "sleep 5 & wait; ls -l" + press ^C
1658 * (What happens to signals which are IGN on shell start?)
1659 * (What happens with signal mask on shell start?)
1661 * Old implementation
1662 * ==================
1663 * We use in-kernel pending signal mask to determine which signals were sent.
1664 * We block all signals which we don't want to take action immediately,
1665 * i.e. we block all signals which need to have special handling as described
1666 * above, and all signals which have traps set.
1667 * After each pipe execution, we extract any pending signals via sigtimedwait()
1670 * unsigned special_sig_mask: a mask of such "special" signals
1671 * sigset_t blocked_set: current blocked signal set
1674 * clear bit in blocked_set unless it is also in special_sig_mask
1675 * "trap 'cmd' SIGxxx":
1676 * set bit in blocked_set (even if 'cmd' is '')
1677 * after [v]fork, if we plan to be a shell:
1678 * unblock signals with special interactive handling
1679 * (child shell is not interactive),
1680 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1681 * after [v]fork, if we plan to exec:
1682 * POSIX says fork clears pending signal mask in child - no need to clear it.
1683 * Restore blocked signal set to one inherited by shell just prior to exec.
1685 * Note: as a result, we do not use signal handlers much. The only uses
1686 * are to count SIGCHLDs
1687 * and to restore tty pgrp on signal-induced exit.
1690 * Standard says "When a subshell is entered, traps that are not being ignored
1691 * are set to the default actions". bash interprets it so that traps which
1692 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1694 * Problem: the above approach makes it unwieldy to catch signals while
1695 * we are in read builtin, or while we read commands from stdin:
1696 * masked signals are not visible!
1698 * New implementation
1699 * ==================
1700 * We record each signal we are interested in by installing signal handler
1701 * for them - a bit like emulating kernel pending signal mask in userspace.
1702 * We are interested in: signals which need to have special handling
1703 * as described above, and all signals which have traps set.
1704 * Signals are recorded in pending_set.
1705 * After each pipe execution, we extract any pending signals
1708 * unsigned special_sig_mask: a mask of shell-special signals.
1709 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1710 * char *traps[sig] if trap for sig is set (even if it's '').
1711 * sigset_t pending_set: set of sigs we received.
1714 * if sig is in special_sig_mask, set handler back to:
1715 * record_pending_signo, or to IGN if it's a tty stop signal
1716 * if sig is in fatal_sig_mask, set handler back to sigexit.
1717 * else: set handler back to SIG_DFL
1718 * "trap 'cmd' SIGxxx":
1719 * set handler to record_pending_signo.
1721 * set handler to SIG_IGN.
1722 * after [v]fork, if we plan to be a shell:
1723 * set signals with special interactive handling to SIG_DFL
1724 * (because child shell is not interactive),
1725 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1726 * after [v]fork, if we plan to exec:
1727 * POSIX says fork clears pending signal mask in child - no need to clear it.
1729 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1730 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1733 * Standard says "When a subshell is entered, traps that are not being ignored
1734 * are set to the default actions". bash interprets it so that traps which
1735 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1738 SPECIAL_INTERACTIVE_SIGS = 0
1743 SPECIAL_JOBSTOP_SIGS = 0
1752 static void record_pending_signo(int sig)
1754 sigaddset(&G.pending_set, sig);
1755 #if ENABLE_HUSH_FAST
1756 if (sig == SIGCHLD) {
1758 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1763 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1765 struct sigaction old_sa;
1767 /* We could use signal() to install handlers... almost:
1768 * except that we need to mask ALL signals while handlers run.
1769 * I saw signal nesting in strace, race window isn't small.
1770 * SA_RESTART is also needed, but in Linux, signal()
1771 * sets SA_RESTART too.
1773 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1774 /* sigfillset(&G.sa.sa_mask); - already done */
1775 /* G.sa.sa_flags = SA_RESTART; - already done */
1776 G.sa.sa_handler = handler;
1777 sigaction(sig, &G.sa, &old_sa);
1778 return old_sa.sa_handler;
1781 static void hush_exit(int exitcode) NORETURN;
1783 static void restore_ttypgrp_and__exit(void) NORETURN;
1784 static void restore_ttypgrp_and__exit(void)
1786 /* xfunc has failed! die die die */
1787 /* no EXIT traps, this is an escape hatch! */
1789 hush_exit(xfunc_error_retval);
1794 /* Needed only on some libc:
1795 * It was observed that on exit(), fgetc'ed buffered data
1796 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1797 * With the net effect that even after fork(), not vfork(),
1798 * exit() in NOEXECed applet in "sh SCRIPT":
1799 * noexec_applet_here
1800 * echo END_OF_SCRIPT
1801 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1802 * This makes "echo END_OF_SCRIPT" executed twice.
1803 * Similar problems can be seen with die_if_script() -> xfunc_die()
1804 * and in `cmd` handling.
1805 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1807 static void fflush_and__exit(void) NORETURN;
1808 static void fflush_and__exit(void)
1811 _exit(xfunc_error_retval);
1814 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1815 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1816 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1817 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1819 /* Restores tty foreground process group, and exits.
1820 * May be called as signal handler for fatal signal
1821 * (will resend signal to itself, producing correct exit state)
1822 * or called directly with -EXITCODE.
1823 * We also call it if xfunc is exiting.
1825 static void sigexit(int sig) NORETURN;
1826 static void sigexit(int sig)
1828 /* Careful: we can end up here after [v]fork. Do not restore
1829 * tty pgrp then, only top-level shell process does that */
1830 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1831 /* Disable all signals: job control, SIGPIPE, etc.
1832 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1834 sigprocmask_allsigs(SIG_BLOCK);
1835 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1838 /* Not a signal, just exit */
1842 kill_myself_with_sig(sig); /* does not return */
1846 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1847 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1851 static sighandler_t pick_sighandler(unsigned sig)
1853 sighandler_t handler = SIG_DFL;
1854 if (sig < sizeof(unsigned)*8) {
1855 unsigned sigmask = (1 << sig);
1859 if (G_fatal_sig_mask & sigmask)
1863 /* sig has special handling? */
1864 if (G.special_sig_mask & sigmask) {
1865 handler = record_pending_signo;
1866 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1867 * in order to ignore them: they will be raised
1868 * in an endless loop when we try to do some
1869 * terminal ioctls! We do have to _ignore_ these.
1871 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1878 /* Restores tty foreground process group, and exits. */
1879 static void hush_exit(int exitcode)
1881 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1882 save_history(G.line_input_state);
1886 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1888 /* argv[0] is unused */
1889 argv[1] = G_traps[0];
1891 G.exiting = 1; /* prevent EXIT trap recursion */
1892 /* Note: G_traps[0] is not cleared!
1893 * "trap" will still show it, if executed
1898 #if ENABLE_FEATURE_CLEAN_UP
1900 struct variable *cur_var;
1901 if (G.cwd != bb_msg_unknown)
1903 cur_var = G.top_var;
1905 struct variable *tmp = cur_var;
1906 if (!cur_var->max_len)
1907 free(cur_var->varstr);
1908 cur_var = cur_var->next;
1916 sigexit(- (exitcode & 0xff));
1923 //TODO: return a mask of ALL handled sigs?
1924 static int check_and_run_traps(void)
1931 if (sigisemptyset(&G.pending_set))
1936 if (sigismember(&G.pending_set, sig)) {
1937 sigdelset(&G.pending_set, sig);
1940 } while (sig < NSIG);
1943 if (G_traps && G_traps[sig]) {
1944 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1945 if (G_traps[sig][0]) {
1946 /* We have user-defined handler */
1947 smalluint save_rcode;
1949 /* argv[0] is unused */
1950 argv[1] = G_traps[sig];
1952 save_rcode = G.last_exitcode;
1954 //FIXME: shouldn't it be set to 128 + sig instead?
1955 G.last_exitcode = save_rcode;
1957 } /* else: "" trap, ignoring signal */
1960 /* not a trap: special action */
1963 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1970 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1971 /* bash is observed to signal whole process groups,
1972 * not individual processes */
1973 for (job = G.job_list; job; job = job->next) {
1976 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1977 if (kill(- job->pgrp, SIGHUP) == 0)
1978 kill(- job->pgrp, SIGCONT);
1983 #if ENABLE_HUSH_FAST
1985 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1987 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1989 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1990 * This simplifies wait builtin a bit.
1994 default: /* ignored: */
1995 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1996 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1998 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1999 * Example: wait is not interrupted by TERM
2000 * in interactive shell, because TERM is ignored.
2009 static const char *get_cwd(int force)
2011 if (force || G.cwd == NULL) {
2012 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2013 * we must not try to free(bb_msg_unknown) */
2014 if (G.cwd == bb_msg_unknown)
2016 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2018 G.cwd = bb_msg_unknown;
2025 * Shell and environment variable support
2027 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2029 struct variable **pp;
2030 struct variable *cur;
2033 while ((cur = *pp) != NULL) {
2034 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2041 static const char* FAST_FUNC get_local_var_value(const char *name)
2043 struct variable **vpp;
2044 unsigned len = strlen(name);
2046 if (G.expanded_assignments) {
2047 char **cpp = G.expanded_assignments;
2050 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2051 return cp + len + 1;
2056 vpp = get_ptr_to_local_var(name, len);
2058 return (*vpp)->varstr + len + 1;
2060 if (strcmp(name, "PPID") == 0)
2061 return utoa(G.root_ppid);
2062 // bash compat: UID? EUID?
2063 #if ENABLE_HUSH_RANDOM_SUPPORT
2064 if (strcmp(name, "RANDOM") == 0)
2065 return utoa(next_random(&G.random_gen));
2070 /* str holds "NAME=VAL" and is expected to be malloced.
2071 * We take ownership of it.
2073 #define SETFLAG_EXPORT (1 << 0)
2074 #define SETFLAG_UNEXPORT (1 << 1)
2075 #define SETFLAG_MAKE_RO (1 << 2)
2076 #define SETFLAG_LOCAL_SHIFT 3
2077 static int set_local_var(char *str, unsigned flags)
2079 struct variable **var_pp;
2080 struct variable *cur;
2081 char *free_me = NULL;
2084 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2086 eq_sign = strchr(str, '=');
2087 if (!eq_sign) { /* not expected to ever happen? */
2092 name_len = eq_sign - str + 1; /* including '=' */
2093 var_pp = &G.top_var;
2094 while ((cur = *var_pp) != NULL) {
2095 if (strncmp(cur->varstr, str, name_len) != 0) {
2096 var_pp = &cur->next;
2100 /* We found an existing var with this name */
2101 if (cur->flg_read_only) {
2102 bb_error_msg("%s: readonly variable", str);
2104 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2105 //but export per se succeeds (does put the var in env). We don't mimic that.
2108 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2109 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2114 #if ENABLE_HUSH_LOCAL
2115 if (cur->func_nest_level < local_lvl) {
2116 /* New variable is declared as local,
2117 * and existing one is global, or local
2118 * from enclosing function.
2119 * Remove and save old one: */
2120 *var_pp = cur->next;
2121 cur->next = *G.shadowed_vars_pp;
2122 *G.shadowed_vars_pp = cur;
2123 /* bash 3.2.33(1) and exported vars:
2125 * # f() { local z=a; env | grep ^z; }
2131 if (cur->flg_export)
2132 flags |= SETFLAG_EXPORT;
2136 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2141 if (cur->max_len != 0) {
2142 if (cur->max_len >= strlen(str)) {
2143 /* This one is from startup env, reuse space */
2144 strcpy(cur->varstr, str);
2149 goto set_str_and_exp;
2151 /* max_len == 0 signifies "malloced" var, which we can
2152 * (and have to) free. But we can't free(cur->varstr) here:
2153 * if cur->flg_export is 1, it is in the environment.
2154 * We should either unsetenv+free, or wait until putenv,
2155 * then putenv(new)+free(old).
2157 free_me = cur->varstr;
2158 goto set_str_and_exp;
2161 /* Not found - create new variable struct */
2162 cur = xzalloc(sizeof(*cur));
2163 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2164 cur->next = *var_pp;
2170 #if !BB_MMU || ENABLE_HUSH_READONLY
2171 if (flags & SETFLAG_MAKE_RO) {
2172 cur->flg_read_only = 1;
2175 if (flags & SETFLAG_EXPORT)
2176 cur->flg_export = 1;
2177 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2178 cmdedit_update_prompt();
2179 if (cur->flg_export) {
2180 if (flags & SETFLAG_UNEXPORT) {
2181 cur->flg_export = 0;
2182 /* unsetenv was already done */
2185 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2186 i = putenv(cur->varstr);
2187 /* only now we can free old exported malloced string */
2196 /* Used at startup and after each cd */
2197 static void set_pwd_var(unsigned flag)
2199 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2202 static int unset_local_var_len(const char *name, int name_len)
2204 struct variable *cur;
2205 struct variable **var_pp;
2208 return EXIT_SUCCESS;
2209 var_pp = &G.top_var;
2210 while ((cur = *var_pp) != NULL) {
2211 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2212 if (cur->flg_read_only) {
2213 bb_error_msg("%s: readonly variable", name);
2214 return EXIT_FAILURE;
2216 *var_pp = cur->next;
2217 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2218 bb_unsetenv(cur->varstr);
2219 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2220 cmdedit_update_prompt();
2224 return EXIT_SUCCESS;
2226 var_pp = &cur->next;
2228 return EXIT_SUCCESS;
2231 #if ENABLE_HUSH_UNSET
2232 static int unset_local_var(const char *name)
2234 return unset_local_var_len(name, strlen(name));
2238 static void unset_vars(char **strings)
2246 const char *eq = strchrnul(*v, '=');
2247 unset_local_var_len(*v, (int)(eq - *v));
2253 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2254 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2256 char *var = xasprintf("%s=%s", name, val);
2257 set_local_var(var, /*flag:*/ 0);
2263 * Helpers for "var1=val1 var2=val2 cmd" feature
2265 static void add_vars(struct variable *var)
2267 struct variable *next;
2271 var->next = G.top_var;
2273 if (var->flg_export) {
2274 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2275 putenv(var->varstr);
2277 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2283 static struct variable *set_vars_and_save_old(char **strings)
2286 struct variable *old = NULL;
2292 struct variable *var_p;
2293 struct variable **var_pp;
2296 eq = strchr(*s, '=');
2298 var_pp = get_ptr_to_local_var(*s, eq - *s);
2301 if (var_p->flg_read_only) {
2303 bb_error_msg("%s: readonly variable", *s);
2305 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2306 * If VAR is readonly, leaving it in the list
2307 * after asssignment error (msg above)
2308 * causes doubled error message later, on unset.
2310 debug_printf_env("removing/freeing '%s' element\n", *s);
2313 do { *p = p[1]; p++; } while (*p);
2316 /* Remove variable from global linked list */
2317 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2318 *var_pp = var_p->next;
2319 /* Add it to returned list */
2323 set_local_var(*s, SETFLAG_EXPORT);
2335 static void reinit_unicode_for_hush(void)
2337 /* Unicode support should be activated even if LANG is set
2338 * _during_ shell execution, not only if it was set when
2339 * shell was started. Therefore, re-check LANG every time:
2341 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2342 || ENABLE_UNICODE_USING_LOCALE
2344 const char *s = get_local_var_value("LC_ALL");
2345 if (!s) s = get_local_var_value("LC_CTYPE");
2346 if (!s) s = get_local_var_value("LANG");
2352 * in_str support (strings, and "strings" read from files).
2355 #if ENABLE_HUSH_INTERACTIVE
2356 /* To test correct lineedit/interactive behavior, type from command line:
2362 * It exercises a lot of corner cases.
2364 static void cmdedit_update_prompt(void)
2366 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2367 G.PS1 = get_local_var_value("PS1");
2370 G.PS2 = get_local_var_value("PS2");
2377 static const char *setup_prompt_string(int promptmode)
2379 const char *prompt_str;
2380 debug_printf("setup_prompt_string %d ", promptmode);
2381 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2382 /* Set up the prompt */
2383 if (promptmode == 0) { /* PS1 */
2385 /* bash uses $PWD value, even if it is set by user.
2386 * It uses current dir only if PWD is unset.
2387 * We always use current dir. */
2388 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2393 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2394 debug_printf("prompt_str '%s'\n", prompt_str);
2397 static int get_user_input(struct in_str *i)
2400 const char *prompt_str;
2402 prompt_str = setup_prompt_string(i->promptmode);
2403 # if ENABLE_FEATURE_EDITING
2405 reinit_unicode_for_hush();
2406 if (G.flag_SIGINT) {
2407 /* There was ^C'ed, make it look prettier: */
2411 /* buglet: SIGINT will not make new prompt to appear _at once_,
2412 * only after <Enter>. (^C works immediately) */
2413 r = read_line_input(G.line_input_state, prompt_str,
2414 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2417 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2419 write(STDOUT_FILENO, "^C", 2);
2422 check_and_run_traps();
2423 if (r != 0 && !G.flag_SIGINT)
2425 /* ^C or SIGINT: repeat */
2426 G.last_exitcode = 128 + SIGINT;
2429 /* EOF/error detected */
2431 i->peek_buf[0] = r = EOF;
2434 i->p = G.user_input_buf;
2435 return (unsigned char)*i->p++;
2439 if (i->last_char == '\0' || i->last_char == '\n') {
2440 /* Why check_and_run_traps here? Try this interactively:
2441 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2442 * $ <[enter], repeatedly...>
2443 * Without check_and_run_traps, handler never runs.
2445 check_and_run_traps();
2446 fputs(prompt_str, stdout);
2449 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2451 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2452 * no ^C masking happens during fgetc, no special code for ^C:
2453 * it generates SIGINT as usual.
2455 check_and_run_traps();
2457 G.last_exitcode = 128 + SIGINT;
2464 /* This is the magic location that prints prompts
2465 * and gets data back from the user */
2466 static int fgetc_interactive(struct in_str *i)
2469 /* If it's interactive stdin, get new line. */
2470 if (G_interactive_fd && i->file == stdin) {
2471 /* Returns first char (or EOF), the rest is in i->p[] */
2472 ch = get_user_input(i);
2473 i->promptmode = 1; /* PS2 */
2475 /* Not stdin: script file, sourced file, etc */
2476 do ch = fgetc(i->file); while (ch == '\0');
2481 static inline int fgetc_interactive(struct in_str *i)
2484 do ch = fgetc(i->file); while (ch == '\0');
2487 #endif /* INTERACTIVE */
2489 static int i_getch(struct in_str *i)
2494 /* string-based in_str */
2495 ch = (unsigned char)*i->p;
2504 /* FILE-based in_str */
2506 #if ENABLE_FEATURE_EDITING
2507 /* This can be stdin, check line editing char[] buffer */
2508 if (i->p && *i->p != '\0') {
2509 ch = (unsigned char)*i->p++;
2513 /* peek_buf[] is an int array, not char. Can contain EOF. */
2514 ch = i->peek_buf[0];
2516 int ch2 = i->peek_buf[1];
2517 i->peek_buf[0] = ch2;
2518 if (ch2 == 0) /* very likely, avoid redundant write */
2524 ch = fgetc_interactive(i);
2526 debug_printf("file_get: got '%c' %d\n", ch, ch);
2531 static int i_peek(struct in_str *i)
2536 /* string-based in_str */
2537 /* Doesn't report EOF on NUL. None of the callers care. */
2538 return (unsigned char)*i->p;
2541 /* FILE-based in_str */
2543 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2544 /* This can be stdin, check line editing char[] buffer */
2545 if (i->p && *i->p != '\0')
2546 return (unsigned char)*i->p;
2548 /* peek_buf[] is an int array, not char. Can contain EOF. */
2549 ch = i->peek_buf[0];
2553 /* Need to get a new char */
2554 ch = fgetc_interactive(i);
2555 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2557 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2558 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2564 i->peek_buf[0] = ch;
2565 /*i->peek_buf[1] = 0; - already is */
2569 /* Only ever called if i_peek() was called, and did not return EOF.
2570 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2571 * not end-of-line. Therefore we never need to read a new editing line here.
2573 static int i_peek2(struct in_str *i)
2577 /* There are two cases when i->p[] buffer exists.
2578 * (1) it's a string in_str.
2579 * (2) It's a file, and we have a saved line editing buffer.
2580 * In both cases, we know that i->p[0] exists and not NUL, and
2581 * the peek2 result is in i->p[1].
2584 return (unsigned char)i->p[1];
2586 /* Now we know it is a file-based in_str. */
2588 /* peek_buf[] is an int array, not char. Can contain EOF. */
2589 /* Is there 2nd char? */
2590 ch = i->peek_buf[1];
2592 /* We did not read it yet, get it now */
2593 do ch = fgetc(i->file); while (ch == '\0');
2594 i->peek_buf[1] = ch;
2597 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2601 static void setup_file_in_str(struct in_str *i, FILE *f)
2603 memset(i, 0, sizeof(*i));
2604 /* i->promptmode = 0; - PS1 (memset did it) */
2609 static void setup_string_in_str(struct in_str *i, const char *s)
2611 memset(i, 0, sizeof(*i));
2612 /* i->promptmode = 0; - PS1 (memset did it) */
2613 /*i->file = NULL */;
2621 #define B_CHUNK (32 * sizeof(char*))
2623 static void o_reset_to_empty_unquoted(o_string *o)
2626 o->has_quoted_part = 0;
2631 static void o_free(o_string *o)
2634 memset(o, 0, sizeof(*o));
2637 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2642 static void o_grow_by(o_string *o, int len)
2644 if (o->length + len > o->maxlen) {
2645 o->maxlen += (2 * len) | (B_CHUNK-1);
2646 o->data = xrealloc(o->data, 1 + o->maxlen);
2650 static void o_addchr(o_string *o, int ch)
2652 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2653 if (o->length < o->maxlen) {
2654 /* likely. avoid o_grow_by() call */
2656 o->data[o->length] = ch;
2658 o->data[o->length] = '\0';
2666 /* Valid only if we know o_string is not empty */
2667 static void o_delchr(o_string *o)
2670 o->data[o->length] = '\0';
2674 static void o_addblock(o_string *o, const char *str, int len)
2677 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2681 static void o_addstr(o_string *o, const char *str)
2683 o_addblock(o, str, strlen(str));
2687 static void nommu_addchr(o_string *o, int ch)
2693 # define nommu_addchr(o, str) ((void)0)
2696 static void o_addstr_with_NUL(o_string *o, const char *str)
2698 o_addblock(o, str, strlen(str) + 1);
2702 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2703 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2704 * Apparently, on unquoted $v bash still does globbing
2705 * ("v='*.txt'; echo $v" prints all .txt files),
2706 * but NOT brace expansion! Thus, there should be TWO independent
2707 * quoting mechanisms on $v expansion side: one protects
2708 * $v from brace expansion, and other additionally protects "$v" against globbing.
2709 * We have only second one.
2712 #if ENABLE_HUSH_BRACE_EXPANSION
2713 # define MAYBE_BRACES "{}"
2715 # define MAYBE_BRACES ""
2718 /* My analysis of quoting semantics tells me that state information
2719 * is associated with a destination, not a source.
2721 static void o_addqchr(o_string *o, int ch)
2724 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2729 o->data[o->length] = '\\';
2732 o->data[o->length] = ch;
2734 o->data[o->length] = '\0';
2737 static void o_addQchr(o_string *o, int ch)
2740 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2741 && strchr("*?[\\" MAYBE_BRACES, ch)
2744 o->data[o->length] = '\\';
2748 o->data[o->length] = ch;
2750 o->data[o->length] = '\0';
2753 static void o_addqblock(o_string *o, const char *str, int len)
2758 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2759 if (ordinary_cnt > len) /* paranoia */
2761 o_addblock(o, str, ordinary_cnt);
2762 if (ordinary_cnt == len)
2763 return; /* NUL is already added by o_addblock */
2764 str += ordinary_cnt;
2765 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2769 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2771 o->data[o->length] = '\\';
2775 o->data[o->length] = ch;
2778 o->data[o->length] = '\0';
2781 static void o_addQblock(o_string *o, const char *str, int len)
2783 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2784 o_addblock(o, str, len);
2787 o_addqblock(o, str, len);
2790 static void o_addQstr(o_string *o, const char *str)
2792 o_addQblock(o, str, strlen(str));
2795 /* A special kind of o_string for $VAR and `cmd` expansion.
2796 * It contains char* list[] at the beginning, which is grown in 16 element
2797 * increments. Actual string data starts at the next multiple of 16 * (char*).
2798 * list[i] contains an INDEX (int!) into this string data.
2799 * It means that if list[] needs to grow, data needs to be moved higher up
2800 * but list[i]'s need not be modified.
2801 * NB: remembering how many list[i]'s you have there is crucial.
2802 * o_finalize_list() operation post-processes this structure - calculates
2803 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2805 #if DEBUG_EXPAND || DEBUG_GLOB
2806 static void debug_print_list(const char *prefix, o_string *o, int n)
2808 char **list = (char**)o->data;
2809 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2813 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2814 prefix, list, n, string_start, o->length, o->maxlen,
2815 !!(o->o_expflags & EXP_FLAG_GLOB),
2817 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2820 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2821 o->data + (int)(uintptr_t)list[i] + string_start,
2822 o->data + (int)(uintptr_t)list[i] + string_start);
2826 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2828 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2832 # define debug_print_list(prefix, o, n) ((void)0)
2835 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2836 * in list[n] so that it points past last stored byte so far.
2837 * It returns n+1. */
2838 static int o_save_ptr_helper(o_string *o, int n)
2840 char **list = (char**)o->data;
2844 if (!o->has_empty_slot) {
2845 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2846 string_len = o->length - string_start;
2847 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2848 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2849 /* list[n] points to string_start, make space for 16 more pointers */
2850 o->maxlen += 0x10 * sizeof(list[0]);
2851 o->data = xrealloc(o->data, o->maxlen + 1);
2852 list = (char**)o->data;
2853 memmove(list + n + 0x10, list + n, string_len);
2854 o->length += 0x10 * sizeof(list[0]);
2856 debug_printf_list("list[%d]=%d string_start=%d\n",
2857 n, string_len, string_start);
2860 /* We have empty slot at list[n], reuse without growth */
2861 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2862 string_len = o->length - string_start;
2863 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2864 n, string_len, string_start);
2865 o->has_empty_slot = 0;
2867 o->has_quoted_part = 0;
2868 list[n] = (char*)(uintptr_t)string_len;
2872 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2873 static int o_get_last_ptr(o_string *o, int n)
2875 char **list = (char**)o->data;
2876 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2878 return ((int)(uintptr_t)list[n-1]) + string_start;
2881 #if ENABLE_HUSH_BRACE_EXPANSION
2882 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2883 * first, it processes even {a} (no commas), second,
2884 * I didn't manage to make it return strings when they don't match
2885 * existing files. Need to re-implement it.
2889 static int glob_needed(const char *s)
2898 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2904 /* Return pointer to next closing brace or to comma */
2905 static const char *next_brace_sub(const char *cp)
2909 while (*cp != '\0') {
2916 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2922 return *cp != '\0' ? cp : NULL;
2924 /* Recursive brace globber. Note: may garble pattern[]. */
2925 static int glob_brace(char *pattern, o_string *o, int n)
2927 char *new_pattern_buf;
2934 debug_printf_glob("glob_brace('%s')\n", pattern);
2940 if (*begin == '{') {
2941 /* Find the first sub-pattern and at the same time
2942 * find the rest after the closing brace */
2943 next = next_brace_sub(begin);
2945 /* An illegal expression */
2949 /* "{abc}" with no commas - illegal
2950 * brace expr, disregard and skip it */
2956 if (*begin == '\\' && begin[1] != '\0')
2960 debug_printf_glob("begin:%s\n", begin);
2961 debug_printf_glob("next:%s\n", next);
2963 /* Now find the end of the whole brace expression */
2965 while (*rest != '}') {
2966 rest = next_brace_sub(rest);
2968 /* An illegal expression */
2971 debug_printf_glob("rest:%s\n", rest);
2973 rest_len = strlen(++rest) + 1;
2975 /* We are sure the brace expression is well-formed */
2977 /* Allocate working buffer large enough for our work */
2978 new_pattern_buf = xmalloc(strlen(pattern));
2980 /* We have a brace expression. BEGIN points to the opening {,
2981 * NEXT points past the terminator of the first element, and REST
2982 * points past the final }. We will accumulate result names from
2983 * recursive runs for each brace alternative in the buffer using
2988 /* Construct the new glob expression */
2991 mempcpy(new_pattern_buf,
2992 /* We know the prefix for all sub-patterns */
2993 pattern, begin - pattern),
2997 /* Note: glob_brace() may garble new_pattern_buf[].
2998 * That's why we re-copy prefix every time (1st memcpy above).
3000 n = glob_brace(new_pattern_buf, o, n);
3002 /* We saw the last entry */
3006 next = next_brace_sub(next);
3008 free(new_pattern_buf);
3016 memset(&globdata, 0, sizeof(globdata));
3017 gr = glob(pattern, 0, NULL, &globdata);
3018 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3020 if (gr == GLOB_NOMATCH) {
3021 globfree(&globdata);
3022 /* NB: garbles parameter */
3023 unbackslash(pattern);
3024 o_addstr_with_NUL(o, pattern);
3025 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3026 return o_save_ptr_helper(o, n);
3028 if (gr == GLOB_NOSPACE)
3029 bb_error_msg_and_die(bb_msg_memory_exhausted);
3030 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3031 * but we didn't specify it. Paranoia again. */
3032 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3034 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3035 char **argv = globdata.gl_pathv;
3037 o_addstr_with_NUL(o, *argv);
3038 n = o_save_ptr_helper(o, n);
3044 globfree(&globdata);
3048 /* Performs globbing on last list[],
3049 * saving each result as a new list[].
3051 static int perform_glob(o_string *o, int n)
3053 char *pattern, *copy;
3055 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3057 return o_save_ptr_helper(o, n);
3058 pattern = o->data + o_get_last_ptr(o, n);
3059 debug_printf_glob("glob pattern '%s'\n", pattern);
3060 if (!glob_needed(pattern)) {
3061 /* unbackslash last string in o in place, fix length */
3062 o->length = unbackslash(pattern) - o->data;
3063 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3064 return o_save_ptr_helper(o, n);
3067 copy = xstrdup(pattern);
3068 /* "forget" pattern in o */
3069 o->length = pattern - o->data;
3070 n = glob_brace(copy, o, n);
3073 debug_print_list("perform_glob returning", o, n);
3077 #else /* !HUSH_BRACE_EXPANSION */
3080 static int glob_needed(const char *s)
3089 if (*s == '*' || *s == '[' || *s == '?')
3095 /* Performs globbing on last list[],
3096 * saving each result as a new list[].
3098 static int perform_glob(o_string *o, int n)
3104 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3106 return o_save_ptr_helper(o, n);
3107 pattern = o->data + o_get_last_ptr(o, n);
3108 debug_printf_glob("glob pattern '%s'\n", pattern);
3109 if (!glob_needed(pattern)) {
3111 /* unbackslash last string in o in place, fix length */
3112 o->length = unbackslash(pattern) - o->data;
3113 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3114 return o_save_ptr_helper(o, n);
3117 memset(&globdata, 0, sizeof(globdata));
3118 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3119 * If we glob "*.\*" and don't find anything, we need
3120 * to fall back to using literal "*.*", but GLOB_NOCHECK
3121 * will return "*.\*"!
3123 gr = glob(pattern, 0, NULL, &globdata);
3124 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3126 if (gr == GLOB_NOMATCH) {
3127 globfree(&globdata);
3130 if (gr == GLOB_NOSPACE)
3131 bb_error_msg_and_die(bb_msg_memory_exhausted);
3132 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3133 * but we didn't specify it. Paranoia again. */
3134 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3136 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3137 char **argv = globdata.gl_pathv;
3138 /* "forget" pattern in o */
3139 o->length = pattern - o->data;
3141 o_addstr_with_NUL(o, *argv);
3142 n = o_save_ptr_helper(o, n);
3148 globfree(&globdata);
3150 debug_print_list("perform_glob returning", o, n);
3154 #endif /* !HUSH_BRACE_EXPANSION */
3156 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3157 * Otherwise, just finish current list[] and start new */
3158 static int o_save_ptr(o_string *o, int n)
3160 if (o->o_expflags & EXP_FLAG_GLOB) {
3161 /* If o->has_empty_slot, list[n] was already globbed
3162 * (if it was requested back then when it was filled)
3163 * so don't do that again! */
3164 if (!o->has_empty_slot)
3165 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3167 return o_save_ptr_helper(o, n);
3170 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3171 static char **o_finalize_list(o_string *o, int n)
3176 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3178 debug_print_list("finalized", o, n);
3179 debug_printf_expand("finalized n:%d\n", n);
3180 list = (char**)o->data;
3181 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3185 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3190 static void free_pipe_list(struct pipe *pi);
3192 /* Returns pi->next - next pipe in the list */
3193 static struct pipe *free_pipe(struct pipe *pi)
3198 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3199 for (i = 0; i < pi->num_cmds; i++) {
3200 struct command *command;
3201 struct redir_struct *r, *rnext;
3203 command = &pi->cmds[i];
3204 debug_printf_clean(" command %d:\n", i);
3205 if (command->argv) {
3209 for (a = 0, p = command->argv; *p; a++, p++) {
3210 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3213 free_strings(command->argv);
3214 //command->argv = NULL;
3216 /* not "else if": on syntax error, we may have both! */
3217 if (command->group) {
3218 debug_printf_clean(" begin group (cmd_type:%d)\n",
3220 free_pipe_list(command->group);
3221 debug_printf_clean(" end group\n");
3222 //command->group = NULL;
3224 /* else is crucial here.
3225 * If group != NULL, child_func is meaningless */
3226 #if ENABLE_HUSH_FUNCTIONS
3227 else if (command->child_func) {
3228 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3229 command->child_func->parent_cmd = NULL;
3233 free(command->group_as_string);
3234 //command->group_as_string = NULL;
3236 for (r = command->redirects; r; r = rnext) {
3237 debug_printf_clean(" redirect %d%s",
3238 r->rd_fd, redir_table[r->rd_type].descrip);
3239 /* guard against the case >$FOO, where foo is unset or blank */
3240 if (r->rd_filename) {
3241 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3242 free(r->rd_filename);
3243 //r->rd_filename = NULL;
3245 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3249 //command->redirects = NULL;
3251 free(pi->cmds); /* children are an array, they get freed all at once */
3255 //pi->cmdtext = NULL;
3263 static void free_pipe_list(struct pipe *pi)
3267 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3269 debug_printf_clean("pipe followup code %d\n", pi->followup);
3275 /*** Parsing routines ***/
3277 #ifndef debug_print_tree
3278 static void debug_print_tree(struct pipe *pi, int lvl)
3280 static const char *const PIPE[] = {
3286 static const char *RES[] = {
3287 [RES_NONE ] = "NONE" ,
3290 [RES_THEN ] = "THEN" ,
3291 [RES_ELIF ] = "ELIF" ,
3292 [RES_ELSE ] = "ELSE" ,
3295 # if ENABLE_HUSH_LOOPS
3296 [RES_FOR ] = "FOR" ,
3297 [RES_WHILE] = "WHILE",
3298 [RES_UNTIL] = "UNTIL",
3300 [RES_DONE ] = "DONE" ,
3302 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3305 # if ENABLE_HUSH_CASE
3306 [RES_CASE ] = "CASE" ,
3307 [RES_CASE_IN ] = "CASE_IN" ,
3308 [RES_MATCH] = "MATCH",
3309 [RES_CASE_BODY] = "CASE_BODY",
3310 [RES_ESAC ] = "ESAC" ,
3312 [RES_XXXX ] = "XXXX" ,
3313 [RES_SNTX ] = "SNTX" ,
3315 static const char *const CMDTYPE[] = {
3319 # if ENABLE_HUSH_FUNCTIONS
3328 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3329 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3331 while (prn < pi->num_cmds) {
3332 struct command *command = &pi->cmds[prn];
3333 char **argv = command->argv;
3335 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3337 command->assignment_cnt);
3338 if (command->group) {
3339 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3340 CMDTYPE[command->cmd_type],
3343 , " group_as_string:", command->group_as_string
3348 debug_print_tree(command->group, lvl+1);
3352 if (argv) while (*argv) {
3353 fdprintf(2, " '%s'", *argv);
3363 #endif /* debug_print_tree */
3365 static struct pipe *new_pipe(void)
3368 pi = xzalloc(sizeof(struct pipe));
3369 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3373 /* Command (member of a pipe) is complete, or we start a new pipe
3374 * if ctx->command is NULL.
3375 * No errors possible here.
3377 static int done_command(struct parse_context *ctx)
3379 /* The command is really already in the pipe structure, so
3380 * advance the pipe counter and make a new, null command. */
3381 struct pipe *pi = ctx->pipe;
3382 struct command *command = ctx->command;
3384 #if 0 /* Instead we emit error message at run time */
3385 if (ctx->pending_redirect) {
3386 /* For example, "cmd >" (no filename to redirect to) */
3387 die_if_script("syntax error: %s", "invalid redirect");
3388 ctx->pending_redirect = NULL;
3393 if (IS_NULL_CMD(command)) {
3394 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3398 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3399 //debug_print_tree(ctx->list_head, 20);
3401 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3404 /* Only real trickiness here is that the uncommitted
3405 * command structure is not counted in pi->num_cmds. */
3406 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3407 ctx->command = command = &pi->cmds[pi->num_cmds];
3409 memset(command, 0, sizeof(*command));
3410 return pi->num_cmds; /* used only for 0/nonzero check */
3413 static void done_pipe(struct parse_context *ctx, pipe_style type)
3417 debug_printf_parse("done_pipe entered, followup %d\n", type);
3418 /* Close previous command */
3419 not_null = done_command(ctx);
3421 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3422 ctx->ctx_inverted = 0;
3423 ctx->pipe->res_word = ctx->ctx_res_w;
3425 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3426 /* Necessary since && and || have precedence over &:
3427 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3428 * in a backgrounded subshell.
3431 struct command *command;
3433 /* Is this actually this construct, all pipes end with && or ||? */
3434 pi = ctx->list_head;
3435 while (pi != ctx->pipe) {
3436 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3441 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3442 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3443 pi = xzalloc(sizeof(*pi));
3444 pi->followup = PIPE_BG;
3446 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3447 command = &pi->cmds[0];
3448 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3449 command->cmd_type = CMD_NORMAL;
3450 command->group = ctx->list_head;
3452 command->group_as_string = xstrndup(
3453 ctx->as_string.data,
3454 ctx->as_string.length - 1 /* do not copy last char, "&" */
3457 /* Replace all pipes in ctx with one newly created */
3458 ctx->list_head = ctx->pipe = pi;
3461 ctx->pipe->followup = type;
3464 /* Without this check, even just <enter> on command line generates
3465 * tree of three NOPs (!). Which is harmless but annoying.
3466 * IOW: it is safe to do it unconditionally. */
3469 || ctx->ctx_res_w == RES_FI
3471 #if ENABLE_HUSH_LOOPS
3472 || ctx->ctx_res_w == RES_DONE
3473 || ctx->ctx_res_w == RES_FOR
3474 || ctx->ctx_res_w == RES_IN
3476 #if ENABLE_HUSH_CASE
3477 || ctx->ctx_res_w == RES_ESAC
3481 debug_printf_parse("done_pipe: adding new pipe: "
3482 "not_null:%d ctx->ctx_res_w:%d\n",
3483 not_null, ctx->ctx_res_w);
3485 ctx->pipe->next = new_p;
3487 /* RES_THEN, RES_DO etc are "sticky" -
3488 * they remain set for pipes inside if/while.
3489 * This is used to control execution.
3490 * RES_FOR and RES_IN are NOT sticky (needed to support
3491 * cases where variable or value happens to match a keyword):
3493 #if ENABLE_HUSH_LOOPS
3494 if (ctx->ctx_res_w == RES_FOR
3495 || ctx->ctx_res_w == RES_IN)
3496 ctx->ctx_res_w = RES_NONE;
3498 #if ENABLE_HUSH_CASE
3499 if (ctx->ctx_res_w == RES_MATCH)
3500 ctx->ctx_res_w = RES_CASE_BODY;
3501 if (ctx->ctx_res_w == RES_CASE)
3502 ctx->ctx_res_w = RES_CASE_IN;
3504 ctx->command = NULL; /* trick done_command below */
3505 /* Create the memory for command, roughly:
3506 * ctx->pipe->cmds = new struct command;
3507 * ctx->command = &ctx->pipe->cmds[0];
3510 //debug_print_tree(ctx->list_head, 10);
3512 debug_printf_parse("done_pipe return\n");
3515 static void initialize_context(struct parse_context *ctx)
3517 memset(ctx, 0, sizeof(*ctx));
3518 ctx->pipe = ctx->list_head = new_pipe();
3519 /* Create the memory for command, roughly:
3520 * ctx->pipe->cmds = new struct command;
3521 * ctx->command = &ctx->pipe->cmds[0];
3526 /* If a reserved word is found and processed, parse context is modified
3527 * and 1 is returned.
3530 struct reserved_combo {
3533 unsigned char assignment_flag;
3537 FLAG_END = (1 << RES_NONE ),
3539 FLAG_IF = (1 << RES_IF ),
3540 FLAG_THEN = (1 << RES_THEN ),
3541 FLAG_ELIF = (1 << RES_ELIF ),
3542 FLAG_ELSE = (1 << RES_ELSE ),
3543 FLAG_FI = (1 << RES_FI ),
3545 # if ENABLE_HUSH_LOOPS
3546 FLAG_FOR = (1 << RES_FOR ),
3547 FLAG_WHILE = (1 << RES_WHILE),
3548 FLAG_UNTIL = (1 << RES_UNTIL),
3549 FLAG_DO = (1 << RES_DO ),
3550 FLAG_DONE = (1 << RES_DONE ),
3551 FLAG_IN = (1 << RES_IN ),
3553 # if ENABLE_HUSH_CASE
3554 FLAG_MATCH = (1 << RES_MATCH),
3555 FLAG_ESAC = (1 << RES_ESAC ),
3557 FLAG_START = (1 << RES_XXXX ),
3560 static const struct reserved_combo* match_reserved_word(o_string *word)
3562 /* Mostly a list of accepted follow-up reserved words.
3563 * FLAG_END means we are done with the sequence, and are ready
3564 * to turn the compound list into a command.
3565 * FLAG_START means the word must start a new compound list.
3567 static const struct reserved_combo reserved_list[] = {
3569 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3570 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3571 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3572 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3573 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3574 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3576 # if ENABLE_HUSH_LOOPS
3577 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3578 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3579 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3580 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3581 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3582 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3584 # if ENABLE_HUSH_CASE
3585 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3586 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3589 const struct reserved_combo *r;
3591 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3592 if (strcmp(word->data, r->literal) == 0)
3597 /* Return 0: not a keyword, 1: keyword
3599 static int reserved_word(o_string *word, struct parse_context *ctx)
3601 # if ENABLE_HUSH_CASE
3602 static const struct reserved_combo reserved_match = {
3603 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3606 const struct reserved_combo *r;
3608 if (word->has_quoted_part)
3610 r = match_reserved_word(word);
3614 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3615 # if ENABLE_HUSH_CASE
3616 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3617 /* "case word IN ..." - IN part starts first MATCH part */
3618 r = &reserved_match;
3621 if (r->flag == 0) { /* '!' */
3622 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3623 syntax_error("! ! command");
3624 ctx->ctx_res_w = RES_SNTX;
3626 ctx->ctx_inverted = 1;
3629 if (r->flag & FLAG_START) {
3630 struct parse_context *old;
3632 old = xmemdup(ctx, sizeof(*ctx));
3633 debug_printf_parse("push stack %p\n", old);
3634 initialize_context(ctx);
3636 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3637 syntax_error_at(word->data);
3638 ctx->ctx_res_w = RES_SNTX;
3641 /* "{...} fi" is ok. "{...} if" is not
3643 * if { echo foo; } then { echo bar; } fi */
3644 if (ctx->command->group)
3645 done_pipe(ctx, PIPE_SEQ);
3648 ctx->ctx_res_w = r->res;
3649 ctx->old_flag = r->flag;
3650 word->o_assignment = r->assignment_flag;
3651 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3653 if (ctx->old_flag & FLAG_END) {
3654 struct parse_context *old;
3656 done_pipe(ctx, PIPE_SEQ);
3657 debug_printf_parse("pop stack %p\n", ctx->stack);
3659 old->command->group = ctx->list_head;
3660 old->command->cmd_type = CMD_NORMAL;
3662 /* At this point, the compound command's string is in
3663 * ctx->as_string... except for the leading keyword!
3664 * Consider this example: "echo a | if true; then echo a; fi"
3665 * ctx->as_string will contain "true; then echo a; fi",
3666 * with "if " remaining in old->as_string!
3670 int len = old->as_string.length;
3671 /* Concatenate halves */
3672 o_addstr(&old->as_string, ctx->as_string.data);
3673 o_free_unsafe(&ctx->as_string);
3674 /* Find where leading keyword starts in first half */
3675 str = old->as_string.data + len;
3676 if (str > old->as_string.data)
3677 str--; /* skip whitespace after keyword */
3678 while (str > old->as_string.data && isalpha(str[-1]))
3680 /* Ugh, we're done with this horrid hack */
3681 old->command->group_as_string = xstrdup(str);
3682 debug_printf_parse("pop, remembering as:'%s'\n",
3683 old->command->group_as_string);
3686 *ctx = *old; /* physical copy */
3691 #endif /* HAS_KEYWORDS */
3693 /* Word is complete, look at it and update parsing context.
3694 * Normal return is 0. Syntax errors return 1.
3695 * Note: on return, word is reset, but not o_free'd!
3697 static int done_word(o_string *word, struct parse_context *ctx)
3699 struct command *command = ctx->command;
3701 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3702 if (word->length == 0 && !word->has_quoted_part) {
3703 debug_printf_parse("done_word return 0: true null, ignored\n");
3707 if (ctx->pending_redirect) {
3708 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3709 * only if run as "bash", not "sh" */
3710 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3712 * ...the word that follows the redirection operator
3713 * shall be subjected to tilde expansion, parameter expansion,
3714 * command substitution, arithmetic expansion, and quote
3715 * removal. Pathname expansion shall not be performed
3716 * on the word by a non-interactive shell; an interactive
3717 * shell may perform it, but shall do so only when
3718 * the expansion would result in one word."
3720 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3721 /* Cater for >\file case:
3722 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3723 * Same with heredocs:
3724 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3726 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3727 unbackslash(ctx->pending_redirect->rd_filename);
3728 /* Is it <<"HEREDOC"? */
3729 if (word->has_quoted_part) {
3730 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3733 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3734 ctx->pending_redirect = NULL;
3737 # if ENABLE_HUSH_CASE
3738 if (ctx->ctx_dsemicolon
3739 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3741 /* already done when ctx_dsemicolon was set to 1: */
3742 /* ctx->ctx_res_w = RES_MATCH; */
3743 ctx->ctx_dsemicolon = 0;
3746 if (!command->argv /* if it's the first word... */
3747 # if ENABLE_HUSH_LOOPS
3748 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3749 && ctx->ctx_res_w != RES_IN
3751 # if ENABLE_HUSH_CASE
3752 && ctx->ctx_res_w != RES_CASE
3755 int reserved = reserved_word(word, ctx);
3756 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3758 o_reset_to_empty_unquoted(word);
3759 debug_printf_parse("done_word return %d\n",
3760 (ctx->ctx_res_w == RES_SNTX));
3761 return (ctx->ctx_res_w == RES_SNTX);
3764 if (strcmp(word->data, "[[") == 0) {
3765 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3771 if (command->group) {
3772 /* "{ echo foo; } echo bar" - bad */
3773 syntax_error_at(word->data);
3774 debug_printf_parse("done_word return 1: syntax error, "
3775 "groups and arglists don't mix\n");
3779 /* If this word wasn't an assignment, next ones definitely
3780 * can't be assignments. Even if they look like ones. */
3781 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3782 && word->o_assignment != WORD_IS_KEYWORD
3784 word->o_assignment = NOT_ASSIGNMENT;
3786 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3787 command->assignment_cnt++;
3788 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3790 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3791 word->o_assignment = MAYBE_ASSIGNMENT;
3793 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3795 if (word->has_quoted_part
3796 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3797 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3798 /* (otherwise it's known to be not empty and is already safe) */
3800 /* exclude "$@" - it can expand to no word despite "" */
3801 char *p = word->data;
3802 while (p[0] == SPECIAL_VAR_SYMBOL
3803 && (p[1] & 0x7f) == '@'
3804 && p[2] == SPECIAL_VAR_SYMBOL
3809 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3810 debug_print_strings("word appended to argv", command->argv);
3813 #if ENABLE_HUSH_LOOPS
3814 if (ctx->ctx_res_w == RES_FOR) {
3815 if (word->has_quoted_part
3816 || !is_well_formed_var_name(command->argv[0], '\0')
3818 /* bash says just "not a valid identifier" */
3819 syntax_error("not a valid identifier in for");
3822 /* Force FOR to have just one word (variable name) */
3823 /* NB: basically, this makes hush see "for v in ..."
3824 * syntax as if it is "for v; in ...". FOR and IN become
3825 * two pipe structs in parse tree. */
3826 done_pipe(ctx, PIPE_SEQ);
3829 #if ENABLE_HUSH_CASE
3830 /* Force CASE to have just one word */
3831 if (ctx->ctx_res_w == RES_CASE) {
3832 done_pipe(ctx, PIPE_SEQ);
3836 o_reset_to_empty_unquoted(word);
3838 debug_printf_parse("done_word return 0\n");
3843 /* Peek ahead in the input to find out if we have a "&n" construct,
3844 * as in "2>&1", that represents duplicating a file descriptor.
3846 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3847 * REDIRFD_SYNTAX_ERR if syntax error,
3848 * REDIRFD_TO_FILE if no & was seen,
3849 * or the number found.
3852 #define parse_redir_right_fd(as_string, input) \
3853 parse_redir_right_fd(input)
3855 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3861 return REDIRFD_TO_FILE;
3863 ch = i_getch(input); /* get the & */
3864 nommu_addchr(as_string, ch);
3867 ch = i_getch(input);
3868 nommu_addchr(as_string, ch);
3869 return REDIRFD_CLOSE;
3873 while (ch != EOF && isdigit(ch)) {
3874 d = d*10 + (ch-'0');
3876 ch = i_getch(input);
3877 nommu_addchr(as_string, ch);
3882 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3884 bb_error_msg("ambiguous redirect");
3885 return REDIRFD_SYNTAX_ERR;
3888 /* Return code is 0 normal, 1 if a syntax error is detected
3890 static int parse_redirect(struct parse_context *ctx,
3893 struct in_str *input)
3895 struct command *command = ctx->command;
3896 struct redir_struct *redir;
3897 struct redir_struct **redirp;
3900 dup_num = REDIRFD_TO_FILE;
3901 if (style != REDIRECT_HEREDOC) {
3902 /* Check for a '>&1' type redirect */
3903 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3904 if (dup_num == REDIRFD_SYNTAX_ERR)
3907 int ch = i_peek(input);
3908 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3909 if (dup_num) { /* <<-... */
3910 ch = i_getch(input);
3911 nommu_addchr(&ctx->as_string, ch);
3916 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3917 int ch = i_peek(input);
3919 /* >|FILE redirect ("clobbering" >).
3920 * Since we do not support "set -o noclobber" yet,
3921 * >| and > are the same for now. Just eat |.
3923 ch = i_getch(input);
3924 nommu_addchr(&ctx->as_string, ch);
3928 /* Create a new redir_struct and append it to the linked list */
3929 redirp = &command->redirects;
3930 while ((redir = *redirp) != NULL) {
3931 redirp = &(redir->next);
3933 *redirp = redir = xzalloc(sizeof(*redir));
3934 /* redir->next = NULL; */
3935 /* redir->rd_filename = NULL; */
3936 redir->rd_type = style;
3937 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3939 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3940 redir_table[style].descrip);
3942 redir->rd_dup = dup_num;
3943 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3944 /* Erik had a check here that the file descriptor in question
3945 * is legit; I postpone that to "run time"
3946 * A "-" representation of "close me" shows up as a -3 here */
3947 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3948 redir->rd_fd, redir->rd_dup);
3950 #if 0 /* Instead we emit error message at run time */
3951 if (ctx->pending_redirect) {
3952 /* For example, "cmd > <file" */
3953 die_if_script("syntax error: %s", "invalid redirect");
3956 /* Set ctx->pending_redirect, so we know what to do at the
3957 * end of the next parsed word. */
3958 ctx->pending_redirect = redir;
3963 /* If a redirect is immediately preceded by a number, that number is
3964 * supposed to tell which file descriptor to redirect. This routine
3965 * looks for such preceding numbers. In an ideal world this routine
3966 * needs to handle all the following classes of redirects...
3967 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3968 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3969 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3970 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3972 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3974 * ... If n is quoted, the number shall not be recognized as part of
3975 * the redirection expression. For example:
3977 * writes the character 2 into file a"
3978 * We are getting it right by setting ->has_quoted_part on any \<char>
3980 * A -1 return means no valid number was found,
3981 * the caller should use the appropriate default for this redirection.
3983 static int redirect_opt_num(o_string *o)
3987 if (o->data == NULL)
3989 num = bb_strtou(o->data, NULL, 10);
3990 if (errno || num < 0)
3992 o_reset_to_empty_unquoted(o);
3997 #define fetch_till_str(as_string, input, word, skip_tabs) \
3998 fetch_till_str(input, word, skip_tabs)
4000 static char *fetch_till_str(o_string *as_string,
4001 struct in_str *input,
4005 o_string heredoc = NULL_O_STRING;
4007 int prev = 0; /* not \ */
4013 ch = i_getch(input);
4015 nommu_addchr(as_string, ch);
4016 if (ch == '\n' || ch == EOF) {
4018 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4019 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4020 heredoc.data[past_EOL] = '\0';
4021 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4022 return heredoc.data;
4025 /* This is a new line.
4026 * Remember position and backslash-escaping status.
4028 o_addchr(&heredoc, ch);
4031 past_EOL = heredoc.length;
4032 /* Get 1st char of next line, possibly skipping leading tabs */
4034 ch = i_getch(input);
4036 nommu_addchr(as_string, ch);
4037 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4038 /* If this immediately ended the line,
4039 * go back to end-of-line checks.
4042 goto check_heredoc_end;
4047 o_free_unsafe(&heredoc);
4050 o_addchr(&heredoc, ch);
4051 nommu_addchr(as_string, ch);
4052 if (prev == '\\' && ch == '\\')
4053 /* Correctly handle foo\\<eol> (not a line cont.) */
4054 prev = 0; /* not \ */
4060 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4061 * and load them all. There should be exactly heredoc_cnt of them.
4063 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4065 struct pipe *pi = ctx->list_head;
4067 while (pi && heredoc_cnt) {
4069 struct command *cmd = pi->cmds;
4071 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4073 cmd->argv ? cmd->argv[0] : "NONE");
4074 for (i = 0; i < pi->num_cmds; i++) {
4075 struct redir_struct *redir = cmd->redirects;
4077 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4078 i, cmd->argv ? cmd->argv[0] : "NONE");
4080 if (redir->rd_type == REDIRECT_HEREDOC) {
4083 redir->rd_type = REDIRECT_HEREDOC2;
4084 /* redir->rd_dup is (ab)used to indicate <<- */
4085 p = fetch_till_str(&ctx->as_string, input,
4086 redir->rd_filename, redir->rd_dup);
4088 syntax_error("unexpected EOF in here document");
4091 free(redir->rd_filename);
4092 redir->rd_filename = p;
4095 redir = redir->next;
4102 /* Should be 0. If it isn't, it's a parse error */
4104 bb_error_msg_and_die("heredoc BUG 2");
4110 static int run_list(struct pipe *pi);
4112 #define parse_stream(pstring, input, end_trigger) \
4113 parse_stream(input, end_trigger)
4115 static struct pipe *parse_stream(char **pstring,
4116 struct in_str *input,
4120 #if !ENABLE_HUSH_FUNCTIONS
4121 #define parse_group(dest, ctx, input, ch) \
4122 parse_group(ctx, input, ch)
4124 static int parse_group(o_string *dest, struct parse_context *ctx,
4125 struct in_str *input, int ch)
4127 /* dest contains characters seen prior to ( or {.
4128 * Typically it's empty, but for function defs,
4129 * it contains function name (without '()'). */
4130 struct pipe *pipe_list;
4132 struct command *command = ctx->command;
4134 debug_printf_parse("parse_group entered\n");
4135 #if ENABLE_HUSH_FUNCTIONS
4136 if (ch == '(' && !dest->has_quoted_part) {
4138 if (done_word(dest, ctx))
4141 goto skip; /* (... */
4142 if (command->argv[1]) { /* word word ... (... */
4143 syntax_error_unexpected_ch('(');
4146 /* it is "word(..." or "word (..." */
4148 ch = i_getch(input);
4149 while (ch == ' ' || ch == '\t');
4151 syntax_error_unexpected_ch(ch);
4154 nommu_addchr(&ctx->as_string, ch);
4156 ch = i_getch(input);
4157 while (ch == ' ' || ch == '\t' || ch == '\n');
4159 syntax_error_unexpected_ch(ch);
4162 nommu_addchr(&ctx->as_string, ch);
4163 command->cmd_type = CMD_FUNCDEF;
4168 #if 0 /* Prevented by caller */
4169 if (command->argv /* word [word]{... */
4170 || dest->length /* word{... */
4171 || dest->has_quoted_part /* ""{... */
4174 debug_printf_parse("parse_group return 1: "
4175 "syntax error, groups and arglists don't mix\n");
4180 #if ENABLE_HUSH_FUNCTIONS
4186 command->cmd_type = CMD_SUBSHELL;
4188 /* bash does not allow "{echo...", requires whitespace */
4190 if (ch != ' ' && ch != '\t' && ch != '\n'
4191 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4193 syntax_error_unexpected_ch(ch);
4197 ch = i_getch(input);
4198 nommu_addchr(&ctx->as_string, ch);
4204 # define as_string NULL
4206 char *as_string = NULL;
4208 pipe_list = parse_stream(&as_string, input, endch);
4211 o_addstr(&ctx->as_string, as_string);
4213 /* empty ()/{} or parse error? */
4214 if (!pipe_list || pipe_list == ERR_PTR) {
4215 /* parse_stream already emitted error msg */
4218 debug_printf_parse("parse_group return 1: "
4219 "parse_stream returned %p\n", pipe_list);
4222 command->group = pipe_list;
4224 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4225 command->group_as_string = as_string;
4226 debug_printf_parse("end of group, remembering as:'%s'\n",
4227 command->group_as_string);
4231 debug_printf_parse("parse_group return 0\n");
4233 /* command remains "open", available for possible redirects */
4236 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4241 ch = i_getch(input);
4244 ch2 = i_peek(input);
4247 /* backslash+newline, skip it */
4252 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4260 ch2 = i_peek2(input);
4263 /* backslash+newline, skip it */
4269 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4270 /* Subroutines for copying $(...) and `...` things */
4271 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4273 static int add_till_single_quote(o_string *dest, struct in_str *input)
4276 int ch = i_getch(input);
4278 syntax_error_unterm_ch('\'');
4286 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4287 static int add_till_double_quote(o_string *dest, struct in_str *input)
4290 int ch = i_getch(input);
4292 syntax_error_unterm_ch('"');
4297 if (ch == '\\') { /* \x. Copy both chars. */
4299 ch = i_getch(input);
4303 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4308 //if (ch == '$') ...
4311 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4313 * "Within the backquoted style of command substitution, backslash
4314 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4315 * The search for the matching backquote shall be satisfied by the first
4316 * backquote found without a preceding backslash; during this search,
4317 * if a non-escaped backquote is encountered within a shell comment,
4318 * a here-document, an embedded command substitution of the $(command)
4319 * form, or a quoted string, undefined results occur. A single-quoted
4320 * or double-quoted string that begins, but does not end, within the
4321 * "`...`" sequence produces undefined results."
4323 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4325 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4328 int ch = i_getch(input);
4332 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4333 ch = i_getch(input);
4337 && (!in_dquote || ch != '"')
4339 o_addchr(dest, '\\');
4343 syntax_error_unterm_ch('`');
4349 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4350 * quoting and nested ()s.
4351 * "With the $(command) style of command substitution, all characters
4352 * following the open parenthesis to the matching closing parenthesis
4353 * constitute the command. Any valid shell script can be used for command,
4354 * except a script consisting solely of redirections which produces
4355 * unspecified results."
4357 * echo $(echo '(TEST)' BEST) (TEST) BEST
4358 * echo $(echo 'TEST)' BEST) TEST) BEST
4359 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4361 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4362 * can contain arbitrary constructs, just like $(cmd).
4363 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4364 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4366 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4367 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4370 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4371 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4372 char end_char2 = end_ch >> 8;
4374 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4377 ch = i_getch(input);
4379 syntax_error_unterm_ch(end_ch);
4383 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4389 /* we look for closing )) of $((EXPR)) */
4390 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4391 i_getch(input); /* eat second ')' */
4396 if (ch == '(' || ch == '{') {
4397 ch = (ch == '(' ? ')' : '}');
4398 if (!add_till_closing_bracket(dest, input, ch))
4404 if (!add_till_single_quote(dest, input))
4410 if (!add_till_double_quote(dest, input))
4416 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4422 /* \x. Copy verbatim. Important for \(, \) */
4423 ch = i_getch(input);
4425 syntax_error_unterm_ch(')');
4430 /* "backslash+newline", ignore both */
4431 o_delchr(dest); /* undo insertion of '\' */
4441 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4443 /* Return code: 0 for OK, 1 for syntax error */
4445 #define parse_dollar(as_string, dest, input, quote_mask) \
4446 parse_dollar(dest, input, quote_mask)
4447 #define as_string NULL
4449 static int parse_dollar(o_string *as_string,
4451 struct in_str *input, unsigned char quote_mask)
4453 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4455 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4457 ch = i_getch(input);
4458 nommu_addchr(as_string, ch);
4460 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4462 debug_printf_parse(": '%c'\n", ch);
4463 o_addchr(dest, ch | quote_mask);
4465 ch = i_peek_and_eat_bkslash_nl(input);
4466 if (!isalnum(ch) && ch != '_') {
4467 /* End of variable name reached */
4470 ch = i_getch(input);
4471 nommu_addchr(as_string, ch);
4473 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4474 } else if (isdigit(ch)) {
4476 ch = i_getch(input);
4477 nommu_addchr(as_string, ch);
4478 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4479 debug_printf_parse(": '%c'\n", ch);
4480 o_addchr(dest, ch | quote_mask);
4481 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4482 } else switch (ch) {
4484 case '!': /* last bg pid */
4485 case '?': /* last exit code */
4486 case '#': /* number of args */
4487 case '*': /* args */
4488 case '@': /* args */
4489 goto make_one_char_var;
4493 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4495 ch = i_getch(input); /* eat '{' */
4496 nommu_addchr(as_string, ch);
4498 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4499 /* It should be ${?}, or ${#var},
4500 * or even ${?+subst} - operator acting on a special variable,
4501 * or the beginning of variable name.
4504 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4507 syntax_error_unterm_str("${name}");
4508 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4511 nommu_addchr(as_string, ch);
4515 /* It's possible to just call add_till_closing_bracket() at this point.
4516 * However, this regresses some of our testsuite cases
4517 * which check invalid constructs like ${%}.
4518 * Oh well... let's check that the var name part is fine... */
4524 debug_printf_parse(": '%c'\n", ch);
4526 ch = i_getch(input);
4527 nommu_addchr(as_string, ch);
4531 if (!isalnum(ch) && ch != '_') {
4533 unsigned char last_ch;
4534 /* handle parameter expansions
4535 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4537 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4538 if (len_single_ch != '#'
4539 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4540 || i_peek(input) != '}'
4542 goto bad_dollar_syntax;
4544 /* else: it's "length of C" ${#C} op,
4545 * where C is a single char
4546 * special var name, e.g. ${#!}.
4549 /* Eat everything until closing '}' (or ':') */
4553 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4555 /* It's ${var:N[:M]} thing */
4556 end_ch = '}' * 0x100 + ':';
4558 if (BASH_PATTERN_SUBST
4561 /* It's ${var/[/]pattern[/repl]} thing */
4562 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4564 nommu_addchr(as_string, '/');
4567 end_ch = '}' * 0x100 + '/';
4573 #if ENABLE_HUSH_DOLLAR_OPS
4574 last_ch = add_till_closing_bracket(dest, input, end_ch);
4575 if (last_ch == 0) /* error? */
4578 #error Simple code to only allow ${var} is not implemented
4581 o_addstr(as_string, dest->data + pos);
4582 o_addchr(as_string, last_ch);
4585 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4586 && (end_ch & 0xff00)
4588 /* close the first block: */
4589 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4590 /* while parsing N from ${var:N[:M]}
4591 * or pattern from ${var/[/]pattern[/repl]} */
4592 if ((end_ch & 0xff) == last_ch) {
4593 /* got ':' or '/'- parse the rest */
4598 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4599 /* it's ${var:N} - emulate :999999999 */
4600 o_addstr(dest, "999999999");
4601 } /* else: it's ${var/[/]pattern} */
4605 len_single_ch = 0; /* it can't be ${#C} op */
4607 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4610 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4614 ch = i_getch(input);
4615 nommu_addchr(as_string, ch);
4616 # if ENABLE_FEATURE_SH_MATH
4617 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4618 ch = i_getch(input);
4619 nommu_addchr(as_string, ch);
4620 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4621 o_addchr(dest, /*quote_mask |*/ '+');
4624 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4625 return 0; /* error */
4627 o_addstr(as_string, dest->data + pos);
4628 o_addchr(as_string, ')');
4629 o_addchr(as_string, ')');
4631 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4635 # if ENABLE_HUSH_TICK
4636 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4637 o_addchr(dest, quote_mask | '`');
4640 if (!add_till_closing_bracket(dest, input, ')'))
4641 return 0; /* error */
4643 o_addstr(as_string, dest->data + pos);
4644 o_addchr(as_string, ')');
4646 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4652 ch = i_getch(input);
4653 nommu_addchr(as_string, ch);
4654 ch = i_peek_and_eat_bkslash_nl(input);
4655 if (isalnum(ch)) { /* it's $_name or $_123 */
4660 /* TODO: $_ and $-: */
4661 /* $_ Shell or shell script name; or last argument of last command
4662 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4663 * but in command's env, set to full pathname used to invoke it */
4664 /* $- Option flags set by set builtin or shell options (-i etc) */
4666 o_addQchr(dest, '$');
4668 debug_printf_parse("parse_dollar return 1 (ok)\n");
4674 # if BASH_PATTERN_SUBST
4675 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4676 encode_string(dest, input, dquote_end, process_bkslash)
4678 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4679 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4680 encode_string(dest, input, dquote_end)
4682 #define as_string NULL
4686 # if BASH_PATTERN_SUBST
4687 /* all parameters are needed, no macro tricks */
4689 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4690 encode_string(as_string, dest, input, dquote_end)
4693 static int encode_string(o_string *as_string,
4695 struct in_str *input,
4697 int process_bkslash)
4699 #if !BASH_PATTERN_SUBST
4700 const int process_bkslash = 1;
4706 ch = i_getch(input);
4708 nommu_addchr(as_string, ch);
4709 if (ch == dquote_end) { /* may be only '"' or EOF */
4710 debug_printf_parse("encode_string return 1 (ok)\n");
4713 /* note: can't move it above ch == dquote_end check! */
4715 syntax_error_unterm_ch('"');
4716 return 0; /* error */
4720 next = i_peek(input);
4722 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4723 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4724 if (process_bkslash && ch == '\\') {
4726 syntax_error("\\<eof>");
4730 * "The backslash retains its special meaning [in "..."]
4731 * only when followed by one of the following characters:
4732 * $, `, ", \, or <newline>. A double quote may be quoted
4733 * within double quotes by preceding it with a backslash."
4734 * NB: in (unquoted) heredoc, above does not apply to ",
4735 * therefore we check for it by "next == dquote_end" cond.
4737 if (next == dquote_end || strchr("$`\\\n", next)) {
4738 ch = i_getch(input); /* eat next */
4740 goto again; /* skip \<newline> */
4741 } /* else: ch remains == '\\', and we double it below: */
4742 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4743 nommu_addchr(as_string, ch);
4747 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4748 debug_printf_parse("encode_string return 0: "
4749 "parse_dollar returned 0 (error)\n");
4754 #if ENABLE_HUSH_TICK
4756 //unsigned pos = dest->length;
4757 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4758 o_addchr(dest, 0x80 | '`');
4759 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4760 return 0; /* error */
4761 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4762 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4766 o_addQchr(dest, ch);
4772 * Scan input until EOF or end_trigger char.
4773 * Return a list of pipes to execute, or NULL on EOF
4774 * or if end_trigger character is met.
4775 * On syntax error, exit if shell is not interactive,
4776 * reset parsing machinery and start parsing anew,
4777 * or return ERR_PTR.
4779 static struct pipe *parse_stream(char **pstring,
4780 struct in_str *input,
4783 struct parse_context ctx;
4784 o_string dest = NULL_O_STRING;
4787 /* Single-quote triggers a bypass of the main loop until its mate is
4788 * found. When recursing, quote state is passed in via dest->o_expflags.
4790 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4791 end_trigger ? end_trigger : 'X');
4794 /* If very first arg is "" or '', dest.data may end up NULL.
4795 * Preventing this: */
4796 o_addchr(&dest, '\0');
4799 /* We used to separate words on $IFS here. This was wrong.
4800 * $IFS is used only for word splitting when $var is expanded,
4801 * here we should use blank chars as separators, not $IFS
4804 if (MAYBE_ASSIGNMENT != 0)
4805 dest.o_assignment = MAYBE_ASSIGNMENT;
4806 initialize_context(&ctx);
4809 const char *is_blank;
4810 const char *is_special;
4814 redir_type redir_style;
4816 ch = i_getch(input);
4817 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4818 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4823 syntax_error_unterm_str("here document");
4826 if (end_trigger == ')') {
4827 syntax_error_unterm_ch('(');
4830 if (end_trigger == '}') {
4831 syntax_error_unterm_ch('{');
4835 if (done_word(&dest, &ctx)) {
4839 done_pipe(&ctx, PIPE_SEQ);
4841 /* If we got nothing... */
4842 /* (this makes bare "&" cmd a no-op.
4843 * bash says: "syntax error near unexpected token '&'") */
4844 if (pi->num_cmds == 0
4845 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4851 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4853 *pstring = ctx.as_string.data;
4855 o_free_unsafe(&ctx.as_string);
4858 debug_printf_parse("parse_stream return %p\n", pi);
4861 nommu_addchr(&ctx.as_string, ch);
4865 next = i_peek(input);
4867 is_special = "{}<>;&|()#'" /* special outside of "str" */
4868 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4869 /* Are { and } special here? */
4870 if (ctx.command->argv /* word [word]{... - non-special */
4871 || dest.length /* word{... - non-special */
4872 || dest.has_quoted_part /* ""{... - non-special */
4873 || (next != ';' /* }; - special */
4874 && next != ')' /* }) - special */
4875 && next != '(' /* {( - special */
4876 && next != '&' /* }& and }&& ... - special */
4877 && next != '|' /* }|| ... - special */
4878 && !strchr(defifs, next) /* {word - non-special */
4881 /* They are not special, skip "{}" */
4884 is_special = strchr(is_special, ch);
4885 is_blank = strchr(defifs, ch);
4887 if (!is_special && !is_blank) { /* ordinary char */
4889 o_addQchr(&dest, ch);
4890 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4891 || dest.o_assignment == WORD_IS_KEYWORD)
4893 && is_well_formed_var_name(dest.data, '=')
4895 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4896 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4902 if (done_word(&dest, &ctx)) {
4906 /* Is this a case when newline is simply ignored?
4908 * "cmd | <newline> cmd ..."
4909 * "case ... in <newline> word) ..."
4911 if (IS_NULL_CMD(ctx.command)
4912 && dest.length == 0 && !dest.has_quoted_part
4914 /* This newline can be ignored. But...
4915 * Without check #1, interactive shell
4916 * ignores even bare <newline>,
4917 * and shows the continuation prompt:
4918 * ps1_prompt$ <enter>
4919 * ps2> _ <=== wrong, should be ps1
4920 * Without check #2, "cmd & <newline>"
4921 * is similarly mistreated.
4922 * (BTW, this makes "cmd & cmd"
4923 * and "cmd && cmd" non-orthogonal.
4924 * Really, ask yourself, why
4925 * "cmd && <newline>" doesn't start
4926 * cmd but waits for more input?
4927 * The only reason is that it might be
4928 * a "cmd1 && <nl> cmd2 &" construct,
4929 * cmd1 may need to run in BG).
4931 struct pipe *pi = ctx.list_head;
4932 if (pi->num_cmds != 0 /* check #1 */
4933 && pi->followup != PIPE_BG /* check #2 */
4938 /* Treat newline as a command separator. */
4939 done_pipe(&ctx, PIPE_SEQ);
4940 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4942 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4947 dest.o_assignment = MAYBE_ASSIGNMENT;
4948 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4950 /* note: if (is_blank) continue;
4951 * will still trigger for us */
4955 /* "cmd}" or "cmd }..." without semicolon or &:
4956 * } is an ordinary char in this case, even inside { cmd; }
4957 * Pathological example: { ""}; } should exec "}" cmd
4960 if (dest.length != 0 /* word} */
4961 || dest.has_quoted_part /* ""} */
4965 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4966 /* Generally, there should be semicolon: "cmd; }"
4967 * However, bash allows to omit it if "cmd" is
4968 * a group. Examples:
4971 * { echo 0 >&2 | { echo 1; } }
4972 * { while false; do :; done }
4973 * { case a in b) ;; esac }
4975 if (ctx.command->group)
4979 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4980 /* Can't be an end of {cmd}, skip the check */
4981 goto skip_end_trigger;
4982 /* else: } does terminate a group */
4985 if (end_trigger && end_trigger == ch
4986 && (ch != ';' || heredoc_cnt == 0)
4987 #if ENABLE_HUSH_CASE
4989 || ctx.ctx_res_w != RES_MATCH
4990 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4995 /* This is technically valid:
4996 * { cat <<HERE; }; echo Ok
5000 * but we don't support this.
5001 * We require heredoc to be in enclosing {}/(),
5004 syntax_error_unterm_str("here document");
5007 if (done_word(&dest, &ctx)) {
5010 done_pipe(&ctx, PIPE_SEQ);
5011 dest.o_assignment = MAYBE_ASSIGNMENT;
5012 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5013 /* Do we sit outside of any if's, loops or case's? */
5015 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5019 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5021 *pstring = ctx.as_string.data;
5023 o_free_unsafe(&ctx.as_string);
5026 debug_printf_parse("parse_stream return %p: "
5027 "end_trigger char found\n",
5029 return ctx.list_head;
5036 /* Catch <, > before deciding whether this word is
5037 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5040 redir_fd = redirect_opt_num(&dest);
5041 if (done_word(&dest, &ctx)) {
5044 redir_style = REDIRECT_OVERWRITE;
5046 redir_style = REDIRECT_APPEND;
5047 ch = i_getch(input);
5048 nommu_addchr(&ctx.as_string, ch);
5051 else if (next == '(') {
5052 syntax_error(">(process) not supported");
5056 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5058 continue; /* back to top of while (1) */
5060 redir_fd = redirect_opt_num(&dest);
5061 if (done_word(&dest, &ctx)) {
5064 redir_style = REDIRECT_INPUT;
5066 redir_style = REDIRECT_HEREDOC;
5068 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5069 ch = i_getch(input);
5070 nommu_addchr(&ctx.as_string, ch);
5071 } else if (next == '>') {
5072 redir_style = REDIRECT_IO;
5073 ch = i_getch(input);
5074 nommu_addchr(&ctx.as_string, ch);
5077 else if (next == '(') {
5078 syntax_error("<(process) not supported");
5082 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5084 continue; /* back to top of while (1) */
5086 if (dest.length == 0 && !dest.has_quoted_part) {
5087 /* skip "#comment" */
5090 if (ch == EOF || ch == '\n')
5093 /* note: we do not add it to &ctx.as_string */
5095 nommu_addchr(&ctx.as_string, '\n');
5096 continue; /* back to top of while (1) */
5101 /* It's "\<newline>" */
5103 /* Remove trailing '\' from ctx.as_string */
5104 ctx.as_string.data[--ctx.as_string.length] = '\0';
5106 ch = i_getch(input); /* eat it */
5107 continue; /* back to top of while (1) */
5112 if (dest.o_assignment == MAYBE_ASSIGNMENT
5113 /* check that we are not in word in "a=1 2>word b=1": */
5114 && !ctx.pending_redirect
5116 /* ch is a special char and thus this word
5117 * cannot be an assignment */
5118 dest.o_assignment = NOT_ASSIGNMENT;
5119 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5122 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5125 case '#': /* non-comment #: "echo a#b" etc */
5126 o_addQchr(&dest, ch);
5130 syntax_error("\\<eof>");
5133 ch = i_getch(input);
5134 /* note: ch != '\n' (that case does not reach this place) */
5135 o_addchr(&dest, '\\');
5136 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5137 o_addchr(&dest, ch);
5138 nommu_addchr(&ctx.as_string, ch);
5139 /* Example: echo Hello \2>file
5140 * we need to know that word 2 is quoted */
5141 dest.has_quoted_part = 1;
5144 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5145 debug_printf_parse("parse_stream parse error: "
5146 "parse_dollar returned 0 (error)\n");
5151 dest.has_quoted_part = 1;
5152 if (next == '\'' && !ctx.pending_redirect) {
5153 insert_empty_quoted_str_marker:
5154 nommu_addchr(&ctx.as_string, next);
5155 i_getch(input); /* eat second ' */
5156 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5157 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5160 ch = i_getch(input);
5162 syntax_error_unterm_ch('\'');
5165 nommu_addchr(&ctx.as_string, ch);
5168 o_addqchr(&dest, ch);
5173 dest.has_quoted_part = 1;
5174 if (next == '"' && !ctx.pending_redirect)
5175 goto insert_empty_quoted_str_marker;
5176 if (dest.o_assignment == NOT_ASSIGNMENT)
5177 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5178 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5180 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5182 #if ENABLE_HUSH_TICK
5184 USE_FOR_NOMMU(unsigned pos;)
5186 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5187 o_addchr(&dest, '`');
5188 USE_FOR_NOMMU(pos = dest.length;)
5189 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5192 o_addstr(&ctx.as_string, dest.data + pos);
5193 o_addchr(&ctx.as_string, '`');
5195 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5196 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5201 #if ENABLE_HUSH_CASE
5204 if (done_word(&dest, &ctx)) {
5207 done_pipe(&ctx, PIPE_SEQ);
5208 #if ENABLE_HUSH_CASE
5209 /* Eat multiple semicolons, detect
5210 * whether it means something special */
5215 ch = i_getch(input);
5216 nommu_addchr(&ctx.as_string, ch);
5217 if (ctx.ctx_res_w == RES_CASE_BODY) {
5218 ctx.ctx_dsemicolon = 1;
5219 ctx.ctx_res_w = RES_MATCH;
5225 /* We just finished a cmd. New one may start
5226 * with an assignment */
5227 dest.o_assignment = MAYBE_ASSIGNMENT;
5228 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5231 if (done_word(&dest, &ctx)) {
5235 ch = i_getch(input);
5236 nommu_addchr(&ctx.as_string, ch);
5237 done_pipe(&ctx, PIPE_AND);
5239 done_pipe(&ctx, PIPE_BG);
5243 if (done_word(&dest, &ctx)) {
5246 #if ENABLE_HUSH_CASE
5247 if (ctx.ctx_res_w == RES_MATCH)
5248 break; /* we are in case's "word | word)" */
5250 if (next == '|') { /* || */
5251 ch = i_getch(input);
5252 nommu_addchr(&ctx.as_string, ch);
5253 done_pipe(&ctx, PIPE_OR);
5255 /* we could pick up a file descriptor choice here
5256 * with redirect_opt_num(), but bash doesn't do it.
5257 * "echo foo 2| cat" yields "foo 2". */
5262 #if ENABLE_HUSH_CASE
5263 /* "case... in [(]word)..." - skip '(' */
5264 if (ctx.ctx_res_w == RES_MATCH
5265 && ctx.command->argv == NULL /* not (word|(... */
5266 && dest.length == 0 /* not word(... */
5267 && dest.has_quoted_part == 0 /* not ""(... */
5273 if (parse_group(&dest, &ctx, input, ch) != 0) {
5278 #if ENABLE_HUSH_CASE
5279 if (ctx.ctx_res_w == RES_MATCH)
5283 /* proper use of this character is caught by end_trigger:
5284 * if we see {, we call parse_group(..., end_trigger='}')
5285 * and it will match } earlier (not here). */
5286 syntax_error_unexpected_ch(ch);
5287 G.last_exitcode = 2;
5291 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5296 G.last_exitcode = 1;
5299 struct parse_context *pctx;
5300 IF_HAS_KEYWORDS(struct parse_context *p2;)
5302 /* Clean up allocated tree.
5303 * Sample for finding leaks on syntax error recovery path.
5304 * Run it from interactive shell, watch pmap `pidof hush`.
5305 * while if false; then false; fi; do break; fi
5306 * Samples to catch leaks at execution:
5307 * while if (true | { true;}); then echo ok; fi; do break; done
5308 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5312 /* Update pipe/command counts,
5313 * otherwise freeing may miss some */
5314 done_pipe(pctx, PIPE_SEQ);
5315 debug_printf_clean("freeing list %p from ctx %p\n",
5316 pctx->list_head, pctx);
5317 debug_print_tree(pctx->list_head, 0);
5318 free_pipe_list(pctx->list_head);
5319 debug_printf_clean("freed list %p\n", pctx->list_head);
5321 o_free_unsafe(&pctx->as_string);
5323 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5327 IF_HAS_KEYWORDS(pctx = p2;)
5328 } while (HAS_KEYWORDS && pctx);
5341 /*** Execution routines ***/
5343 /* Expansion can recurse, need forward decls: */
5344 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5345 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5346 #define expand_string_to_string(str, do_unbackslash) \
5347 expand_string_to_string(str)
5349 static char *expand_string_to_string(const char *str, int do_unbackslash);
5350 #if ENABLE_HUSH_TICK
5351 static int process_command_subs(o_string *dest, const char *s);
5354 /* expand_strvec_to_strvec() takes a list of strings, expands
5355 * all variable references within and returns a pointer to
5356 * a list of expanded strings, possibly with larger number
5357 * of strings. (Think VAR="a b"; echo $VAR).
5358 * This new list is allocated as a single malloc block.
5359 * NULL-terminated list of char* pointers is at the beginning of it,
5360 * followed by strings themselves.
5361 * Caller can deallocate entire list by single free(list). */
5363 /* A horde of its helpers come first: */
5365 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5367 while (--len >= 0) {
5370 #if ENABLE_HUSH_BRACE_EXPANSION
5371 if (c == '{' || c == '}') {
5372 /* { -> \{, } -> \} */
5374 /* And now we want to add { or } and continue:
5377 * luckily, just falling through achieves this.
5383 /* \z -> \\\z; \<eol> -> \\<eol> */
5388 o_addchr(o, *str++);
5394 /* Store given string, finalizing the word and starting new one whenever
5395 * we encounter IFS char(s). This is used for expanding variable values.
5396 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5397 * Return in *ended_with_ifs:
5398 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5400 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5402 int last_is_ifs = 0;
5407 if (!*str) /* EOL - do not finalize word */
5409 word_len = strcspn(str, G.ifs);
5411 /* We have WORD_LEN leading non-IFS chars */
5412 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5413 o_addblock(output, str, word_len);
5415 /* Protect backslashes against globbing up :)
5416 * Example: "v='\*'; echo b$v" prints "b\*"
5417 * (and does not try to glob on "*")
5419 o_addblock_duplicate_backslash(output, str, word_len);
5420 /*/ Why can't we do it easier? */
5421 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5422 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5426 if (!*str) /* EOL - do not finalize word */
5430 /* We know str here points to at least one IFS char */
5432 str += strspn(str, G.ifs); /* skip IFS chars */
5433 if (!*str) /* EOL - do not finalize word */
5436 /* Start new word... but not always! */
5437 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5438 if (output->has_quoted_part
5439 /* Case "v=' a'; echo $v":
5440 * here nothing precedes the space in $v expansion,
5441 * therefore we should not finish the word
5442 * (IOW: if there *is* word to finalize, only then do it):
5444 || (n > 0 && output->data[output->length - 1])
5446 o_addchr(output, '\0');
5447 debug_print_list("expand_on_ifs", output, n);
5448 n = o_save_ptr(output, n);
5453 *ended_with_ifs = last_is_ifs;
5454 debug_print_list("expand_on_ifs[1]", output, n);
5458 /* Helper to expand $((...)) and heredoc body. These act as if
5459 * they are in double quotes, with the exception that they are not :).
5460 * Just the rules are similar: "expand only $var and `cmd`"
5462 * Returns malloced string.
5463 * As an optimization, we return NULL if expansion is not needed.
5465 #if !BASH_PATTERN_SUBST
5466 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5467 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5468 encode_then_expand_string(str)
5470 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5472 #if !BASH_PATTERN_SUBST
5473 const int do_unbackslash = 1;
5476 struct in_str input;
5477 o_string dest = NULL_O_STRING;
5479 if (!strchr(str, '$')
5480 && !strchr(str, '\\')
5481 #if ENABLE_HUSH_TICK
5482 && !strchr(str, '`')
5488 /* We need to expand. Example:
5489 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5491 setup_string_in_str(&input, str);
5492 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5493 //TODO: error check (encode_string returns 0 on error)?
5494 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5495 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5496 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5497 o_free_unsafe(&dest);
5501 #if ENABLE_FEATURE_SH_MATH
5502 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5504 arith_state_t math_state;
5508 math_state.lookupvar = get_local_var_value;
5509 math_state.setvar = set_local_var_from_halves;
5510 //math_state.endofname = endofname;
5511 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5512 res = arith(&math_state, exp_str ? exp_str : arg);
5515 *errmsg_p = math_state.errmsg;
5516 if (math_state.errmsg)
5517 die_if_script(math_state.errmsg);
5522 #if BASH_PATTERN_SUBST
5523 /* ${var/[/]pattern[/repl]} helpers */
5524 static char *strstr_pattern(char *val, const char *pattern, int *size)
5527 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5528 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5535 /* Optimization: if "*pat" did not match the start of "string",
5536 * we know that "tring", "ring" etc will not match too:
5538 if (pattern[0] == '*')
5543 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5545 char *result = NULL;
5546 unsigned res_len = 0;
5547 unsigned repl_len = strlen(repl);
5551 char *s = strstr_pattern(val, pattern, &size);
5555 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5556 strcpy(mempcpy(result + res_len, val, s - val), repl);
5557 res_len += (s - val) + repl_len;
5558 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5564 if (*val && result) {
5565 result = xrealloc(result, res_len + strlen(val) + 1);
5566 strcpy(result + res_len, val);
5567 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5569 debug_printf_varexp("result:'%s'\n", result);
5572 #endif /* BASH_PATTERN_SUBST */
5575 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5577 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5579 const char *val = NULL;
5580 char *to_be_freed = NULL;
5585 char exp_save = exp_save; /* for compiler */
5586 char *exp_saveptr; /* points to expansion operator */
5587 char *exp_word = exp_word; /* for compiler */
5590 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5592 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5594 first_char = arg[0] = arg0 & 0x7f;
5597 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5598 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5599 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5600 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5602 /* It must be length operator: ${#var} */
5606 /* Maybe handle parameter expansion */
5607 if (exp_saveptr /* if 2nd char is one of expansion operators */
5608 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5610 /* ${?:0}, ${#[:]%0} etc */
5611 exp_saveptr = var + 1;
5613 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5614 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5616 exp_op = exp_save = *exp_saveptr;
5618 exp_word = exp_saveptr + 1;
5619 if (exp_op == ':') {
5620 exp_op = *exp_word++;
5621 //TODO: try ${var:} and ${var:bogus} in non-bash config
5623 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5625 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5630 *exp_saveptr = '\0';
5631 } /* else: it's not an expansion op, but bare ${var} */
5634 /* Look up the variable in question */
5635 if (isdigit(var[0])) {
5636 /* parse_dollar should have vetted var for us */
5637 int n = xatoi_positive(var);
5638 if (n < G.global_argc)
5639 val = G.global_argv[n];
5640 /* else val remains NULL: $N with too big N */
5644 val = utoa(G.root_pid);
5646 case '!': /* bg pid */
5647 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5649 case '?': /* exitcode */
5650 val = utoa(G.last_exitcode);
5652 case '#': /* argc */
5653 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5656 val = get_local_var_value(var);
5660 /* Handle any expansions */
5661 if (exp_op == 'L') {
5662 reinit_unicode_for_hush();
5663 debug_printf_expand("expand: length(%s)=", val);
5664 val = utoa(val ? unicode_strlen(val) : 0);
5665 debug_printf_expand("%s\n", val);
5666 } else if (exp_op) {
5667 if (exp_op == '%' || exp_op == '#') {
5668 /* Standard-mandated substring removal ops:
5669 * ${parameter%word} - remove smallest suffix pattern
5670 * ${parameter%%word} - remove largest suffix pattern
5671 * ${parameter#word} - remove smallest prefix pattern
5672 * ${parameter##word} - remove largest prefix pattern
5674 * Word is expanded to produce a glob pattern.
5675 * Then var's value is matched to it and matching part removed.
5677 if (val && val[0]) {
5681 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5682 if (exp_op == *exp_word) /* ## or %% */
5684 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5686 exp_word = exp_exp_word;
5687 /* HACK ALERT. We depend here on the fact that
5688 * G.global_argv and results of utoa and get_local_var_value
5689 * are actually in writable memory:
5690 * scan_and_match momentarily stores NULs there. */
5692 loc = scan_and_match(t, exp_word, scan_flags);
5693 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5694 // exp_op, t, exp_word, loc);
5696 if (loc) { /* match was found */
5697 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5698 val = loc; /* take right part */
5700 val = to_be_freed = xstrndup(val, loc - val); /* left */
5704 #if BASH_PATTERN_SUBST
5705 else if (exp_op == '/' || exp_op == '\\') {
5706 /* It's ${var/[/]pattern[/repl]} thing.
5707 * Note that in encoded form it has TWO parts:
5708 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5709 * and if // is used, it is encoded as \:
5710 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5712 /* Empty variable always gives nothing: */
5713 // "v=''; echo ${v/*/w}" prints "", not "w"
5714 if (val && val[0]) {
5715 /* pattern uses non-standard expansion.
5716 * repl should be unbackslashed and globbed
5717 * by the usual expansion rules:
5719 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5720 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5721 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5722 * v='a bz'; echo ${v/a*z/\z} prints "z"
5723 * (note that a*z _pattern_ is never globbed!)
5725 char *pattern, *repl, *t;
5726 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5728 pattern = xstrdup(exp_word);
5729 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5730 *p++ = SPECIAL_VAR_SYMBOL;
5732 p = strchr(p, SPECIAL_VAR_SYMBOL);
5734 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5735 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5736 /* HACK ALERT. We depend here on the fact that
5737 * G.global_argv and results of utoa and get_local_var_value
5738 * are actually in writable memory:
5739 * replace_pattern momentarily stores NULs there. */
5741 to_be_freed = replace_pattern(t,
5743 (repl ? repl : exp_word),
5745 if (to_be_freed) /* at least one replace happened */
5751 #endif /* BASH_PATTERN_SUBST */
5752 else if (exp_op == ':') {
5753 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5754 /* It's ${var:N[:M]} bashism.
5755 * Note that in encoded form it has TWO parts:
5756 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5761 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5764 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5765 *p++ = SPECIAL_VAR_SYMBOL;
5767 p = strchr(p, SPECIAL_VAR_SYMBOL);
5769 len = expand_and_evaluate_arith(exp_word, &errmsg);
5772 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5774 /* negative beg counts from the end */
5775 beg = (arith_t)strlen(val) + beg;
5776 if (beg < 0) /* ${v: -999999} is "" */
5779 debug_printf_varexp("from val:'%s'\n", val);
5781 /* in bash, len=-n means strlen()-n */
5782 len = (arith_t)strlen(val) - beg + len;
5783 if (len < 0) /* bash compat */
5784 die_if_script("%s: substring expression < 0", var);
5786 if (len <= 0 || !val || beg >= strlen(val)) {
5790 /* Paranoia. What if user entered 9999999999999
5791 * which fits in arith_t but not int? */
5794 val = to_be_freed = xstrndup(val + beg, len);
5796 debug_printf_varexp("val:'%s'\n", val);
5797 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5798 die_if_script("malformed ${%s:...}", var);
5801 } else { /* one of "-=+?" */
5802 /* Standard-mandated substitution ops:
5803 * ${var?word} - indicate error if unset
5804 * If var is unset, word (or a message indicating it is unset
5805 * if word is null) is written to standard error
5806 * and the shell exits with a non-zero exit status.
5807 * Otherwise, the value of var is substituted.
5808 * ${var-word} - use default value
5809 * If var is unset, word is substituted.
5810 * ${var=word} - assign and use default value
5811 * If var is unset, word is assigned to var.
5812 * In all cases, final value of var is substituted.
5813 * ${var+word} - use alternative value
5814 * If var is unset, null is substituted.
5815 * Otherwise, word is substituted.
5817 * Word is subjected to tilde expansion, parameter expansion,
5818 * command substitution, and arithmetic expansion.
5819 * If word is not needed, it is not expanded.
5821 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5822 * but also treat null var as if it is unset.
5824 int use_word = (!val || ((exp_save == ':') && !val[0]));
5826 use_word = !use_word;
5827 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5828 (exp_save == ':') ? "true" : "false", use_word);
5830 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5832 exp_word = to_be_freed;
5833 if (exp_op == '?') {
5834 /* mimic bash message */
5835 die_if_script("%s: %s",
5839 : "parameter null or not set"
5840 /* ash has more specific messages, a-la: */
5841 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5843 //TODO: how interactive bash aborts expansion mid-command?
5848 if (exp_op == '=') {
5849 /* ${var=[word]} or ${var:=[word]} */
5850 if (isdigit(var[0]) || var[0] == '#') {
5851 /* mimic bash message */
5852 die_if_script("$%s: cannot assign in this way", var);
5855 char *new_var = xasprintf("%s=%s", var, val);
5856 set_local_var(new_var, /*flag:*/ 0);
5860 } /* one of "-=+?" */
5862 *exp_saveptr = exp_save;
5868 *to_be_freed_pp = to_be_freed;
5872 /* Expand all variable references in given string, adding words to list[]
5873 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5874 * to be filled). This routine is extremely tricky: has to deal with
5875 * variables/parameters with whitespace, $* and $@, and constructs like
5876 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5877 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5879 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5880 * expansion of right-hand side of assignment == 1-element expand.
5882 char cant_be_null = 0; /* only bit 0x80 matters */
5883 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5886 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5887 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5888 debug_print_list("expand_vars_to_list", output, n);
5889 n = o_save_ptr(output, n);
5890 debug_print_list("expand_vars_to_list[0]", output, n);
5892 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5894 char *to_be_freed = NULL;
5895 const char *val = NULL;
5896 #if ENABLE_HUSH_TICK
5897 o_string subst_result = NULL_O_STRING;
5899 #if ENABLE_FEATURE_SH_MATH
5900 char arith_buf[sizeof(arith_t)*3 + 2];
5904 o_addchr(output, '\0');
5905 n = o_save_ptr(output, n);
5909 o_addblock(output, arg, p - arg);
5910 debug_print_list("expand_vars_to_list[1]", output, n);
5912 p = strchr(p, SPECIAL_VAR_SYMBOL);
5914 /* Fetch special var name (if it is indeed one of them)
5915 * and quote bit, force the bit on if singleword expansion -
5916 * important for not getting v=$@ expand to many words. */
5917 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5919 /* Is this variable quoted and thus expansion can't be null?
5920 * "$@" is special. Even if quoted, it can still
5921 * expand to nothing (not even an empty string),
5922 * thus it is excluded. */
5923 if ((first_ch & 0x7f) != '@')
5924 cant_be_null |= first_ch;
5926 switch (first_ch & 0x7f) {
5927 /* Highest bit in first_ch indicates that var is double-quoted */
5931 if (!G.global_argv[1])
5934 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5935 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5936 while (G.global_argv[i]) {
5937 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5938 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5939 if (G.global_argv[i++][0] && G.global_argv[i]) {
5940 /* this argv[] is not empty and not last:
5941 * put terminating NUL, start new word */
5942 o_addchr(output, '\0');
5943 debug_print_list("expand_vars_to_list[2]", output, n);
5944 n = o_save_ptr(output, n);
5945 debug_print_list("expand_vars_to_list[3]", output, n);
5949 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5950 * and in this case should treat it like '$*' - see 'else...' below */
5951 if (first_ch == ('@'|0x80) /* quoted $@ */
5952 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5955 o_addQstr(output, G.global_argv[i]);
5956 if (++i >= G.global_argc)
5958 o_addchr(output, '\0');
5959 debug_print_list("expand_vars_to_list[4]", output, n);
5960 n = o_save_ptr(output, n);
5962 } else { /* quoted $* (or v="$@" case): add as one word */
5964 o_addQstr(output, G.global_argv[i]);
5965 if (!G.global_argv[++i])
5968 o_addchr(output, G.ifs[0]);
5970 output->has_quoted_part = 1;
5974 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5975 /* "Empty variable", used to make "" etc to not disappear */
5976 output->has_quoted_part = 1;
5978 cant_be_null = 0x80;
5980 #if ENABLE_HUSH_TICK
5981 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5982 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5984 /* Can't just stuff it into output o_string,
5985 * expanded result may need to be globbed
5987 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5988 G.last_exitcode = process_command_subs(&subst_result, arg);
5989 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5990 val = subst_result.data;
5993 #if ENABLE_FEATURE_SH_MATH
5994 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5997 arg++; /* skip '+' */
5998 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5999 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
6000 res = expand_and_evaluate_arith(arg, NULL);
6001 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
6002 sprintf(arith_buf, ARITH_FMT, res);
6008 val = expand_one_var(&to_be_freed, arg, &p);
6009 IF_HUSH_TICK(store_val:)
6010 if (!(first_ch & 0x80)) { /* unquoted $VAR */
6011 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6012 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6013 if (val && val[0]) {
6014 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6017 } else { /* quoted $VAR, val will be appended below */
6018 output->has_quoted_part = 1;
6019 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6020 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6023 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6025 if (val && val[0]) {
6026 o_addQstr(output, val);
6030 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6031 * Do the check to avoid writing to a const string. */
6032 if (*p != SPECIAL_VAR_SYMBOL)
6033 *p = SPECIAL_VAR_SYMBOL;
6035 #if ENABLE_HUSH_TICK
6036 o_free(&subst_result);
6039 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6043 o_addchr(output, '\0');
6044 n = o_save_ptr(output, n);
6046 debug_print_list("expand_vars_to_list[a]", output, n);
6047 /* this part is literal, and it was already pre-quoted
6048 * if needed (much earlier), do not use o_addQstr here! */
6049 o_addstr_with_NUL(output, arg);
6050 debug_print_list("expand_vars_to_list[b]", output, n);
6051 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6052 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6055 /* allow to reuse list[n] later without re-growth */
6056 output->has_empty_slot = 1;
6058 o_addchr(output, '\0');
6064 static char **expand_variables(char **argv, unsigned expflags)
6068 o_string output = NULL_O_STRING;
6070 output.o_expflags = expflags;
6074 n = expand_vars_to_list(&output, n, *argv);
6077 debug_print_list("expand_variables", &output, n);
6079 /* output.data (malloced in one block) gets returned in "list" */
6080 list = o_finalize_list(&output, n);
6081 debug_print_strings("expand_variables[1]", list);
6085 static char **expand_strvec_to_strvec(char **argv)
6087 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6091 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6093 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6097 /* Used for expansion of right hand of assignments,
6098 * $((...)), heredocs, variable espansion parts.
6100 * NB: should NOT do globbing!
6101 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6103 static char *expand_string_to_string(const char *str, int do_unbackslash)
6105 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6106 const int do_unbackslash = 1;
6108 char *argv[2], **list;
6110 debug_printf_expand("string_to_string<='%s'\n", str);
6111 /* This is generally an optimization, but it also
6112 * handles "", which otherwise trips over !list[0] check below.
6113 * (is this ever happens that we actually get str="" here?)
6115 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6116 //TODO: Can use on strings with \ too, just unbackslash() them?
6117 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6118 return xstrdup(str);
6121 argv[0] = (char*)str;
6123 list = expand_variables(argv, do_unbackslash
6124 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6125 : EXP_FLAG_SINGLEWORD
6128 if (!list[0] || list[1])
6129 bb_error_msg_and_die("BUG in varexp2");
6130 /* actually, just move string 2*sizeof(char*) bytes back */
6131 overlapping_strcpy((char*)list, list[0]);
6133 unbackslash((char*)list);
6134 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6138 /* Used for "eval" builtin and case string */
6139 static char* expand_strvec_to_string(char **argv)
6143 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6144 /* Convert all NULs to spaces */
6149 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6150 bb_error_msg_and_die("BUG in varexp3");
6151 /* bash uses ' ' regardless of $IFS contents */
6156 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6157 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6161 static char **expand_assignments(char **argv, int count)
6166 G.expanded_assignments = p = NULL;
6167 /* Expand assignments into one string each */
6168 for (i = 0; i < count; i++) {
6169 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6171 G.expanded_assignments = NULL;
6176 static void switch_off_special_sigs(unsigned mask)
6179 while ((mask >>= 1) != 0) {
6183 #if ENABLE_HUSH_TRAP
6185 if (G_traps[sig] && !G_traps[sig][0])
6186 /* trap is '', has to remain SIG_IGN */
6189 G_traps[sig] = NULL;
6192 /* We are here only if no trap or trap was not '' */
6193 install_sighandler(sig, SIG_DFL);
6199 void re_execute_shell(char ***to_free, const char *s,
6200 char *g_argv0, char **g_argv,
6201 char **builtin_argv) NORETURN;
6203 static void reset_traps_to_defaults(void)
6205 /* This function is always called in a child shell
6206 * after fork (not vfork, NOMMU doesn't use this function).
6208 IF_HUSH_TRAP(unsigned sig;)
6211 /* Child shells are not interactive.
6212 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6213 * Testcase: (while :; do :; done) + ^Z should background.
6214 * Same goes for SIGTERM, SIGHUP, SIGINT.
6216 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6217 if (!G_traps && !mask)
6218 return; /* already no traps and no special sigs */
6220 /* Switch off special sigs */
6221 switch_off_special_sigs(mask);
6222 # if ENABLE_HUSH_JOB
6223 G_fatal_sig_mask = 0;
6225 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6226 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6227 * remain set in G.special_sig_mask */
6229 # if ENABLE_HUSH_TRAP
6233 /* Reset all sigs to default except ones with empty traps */
6234 for (sig = 0; sig < NSIG; sig++) {
6236 continue; /* no trap: nothing to do */
6237 if (!G_traps[sig][0])
6238 continue; /* empty trap: has to remain SIG_IGN */
6239 /* sig has non-empty trap, reset it: */
6241 G_traps[sig] = NULL;
6242 /* There is no signal for trap 0 (EXIT) */
6245 install_sighandler(sig, pick_sighandler(sig));
6252 static void re_execute_shell(char ***to_free, const char *s,
6253 char *g_argv0, char **g_argv,
6254 char **builtin_argv) NORETURN;
6255 static void re_execute_shell(char ***to_free, const char *s,
6256 char *g_argv0, char **g_argv,
6257 char **builtin_argv)
6259 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6260 /* delims + 2 * (number of bytes in printed hex numbers) */
6261 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6262 char *heredoc_argv[4];
6263 struct variable *cur;
6264 # if ENABLE_HUSH_FUNCTIONS
6265 struct function *funcp;
6269 unsigned long long empty_trap_mask;
6271 if (!g_argv0) { /* heredoc */
6272 argv = heredoc_argv;
6273 argv[0] = (char *) G.argv0_for_re_execing;
6274 argv[1] = (char *) "-<";
6275 argv[2] = (char *) s;
6277 pp = &argv[3]; /* used as pointer to empty environment */
6283 if (pp) while (*pp++)
6286 empty_trap_mask = 0;
6289 for (sig = 1; sig < NSIG; sig++) {
6290 if (G_traps[sig] && !G_traps[sig][0])
6291 empty_trap_mask |= 1LL << sig;
6295 sprintf(param_buf, NOMMU_HACK_FMT
6296 , (unsigned) G.root_pid
6297 , (unsigned) G.root_ppid
6298 , (unsigned) G.last_bg_pid
6299 , (unsigned) G.last_exitcode
6302 IF_HUSH_LOOPS(, G.depth_of_loop)
6304 # undef NOMMU_HACK_FMT
6305 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6306 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6309 for (cur = G.top_var; cur; cur = cur->next) {
6310 if (!cur->flg_export || cur->flg_read_only)
6313 # if ENABLE_HUSH_FUNCTIONS
6314 for (funcp = G.top_func; funcp; funcp = funcp->next)
6320 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6321 *pp++ = (char *) G.argv0_for_re_execing;
6323 for (cur = G.top_var; cur; cur = cur->next) {
6324 if (strcmp(cur->varstr, hush_version_str) == 0)
6326 if (cur->flg_read_only) {
6327 *pp++ = (char *) "-R";
6328 *pp++ = cur->varstr;
6329 } else if (!cur->flg_export) {
6330 *pp++ = (char *) "-V";
6331 *pp++ = cur->varstr;
6334 # if ENABLE_HUSH_FUNCTIONS
6335 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6336 *pp++ = (char *) "-F";
6337 *pp++ = funcp->name;
6338 *pp++ = funcp->body_as_string;
6341 /* We can pass activated traps here. Say, -Tnn:trap_string
6343 * However, POSIX says that subshells reset signals with traps
6345 * I tested bash-3.2 and it not only does that with true subshells
6346 * of the form ( list ), but with any forked children shells.
6347 * I set trap "echo W" WINCH; and then tried:
6349 * { echo 1; sleep 20; echo 2; } &
6350 * while true; do echo 1; sleep 20; echo 2; break; done &
6351 * true | { echo 1; sleep 20; echo 2; } | cat
6353 * In all these cases sending SIGWINCH to the child shell
6354 * did not run the trap. If I add trap "echo V" WINCH;
6355 * _inside_ group (just before echo 1), it works.
6357 * I conclude it means we don't need to pass active traps here.
6359 *pp++ = (char *) "-c";
6362 while (*++builtin_argv)
6363 *pp++ = *builtin_argv;
6364 *pp++ = (char *) "";
6369 /* *pp = NULL; - is already there */
6373 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6374 /* Don't propagate SIG_IGN to the child */
6375 if (SPECIAL_JOBSTOP_SIGS != 0)
6376 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6377 execve(bb_busybox_exec_path, argv, pp);
6378 /* Fallback. Useful for init=/bin/hush usage etc */
6379 if (argv[0][0] == '/')
6380 execve(argv[0], argv, pp);
6381 xfunc_error_retval = 127;
6382 bb_error_msg_and_die("can't re-execute the shell");
6384 #endif /* !BB_MMU */
6387 static int run_and_free_list(struct pipe *pi);
6389 /* Executing from string: eval, sh -c '...'
6390 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6391 * end_trigger controls how often we stop parsing
6392 * NUL: parse all, execute, return
6393 * ';': parse till ';' or newline, execute, repeat till EOF
6395 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6397 /* Why we need empty flag?
6398 * An obscure corner case "false; ``; echo $?":
6399 * empty command in `` should still set $? to 0.
6400 * But we can't just set $? to 0 at the start,
6401 * this breaks "false; echo `echo $?`" case.
6405 struct pipe *pipe_list;
6407 #if ENABLE_HUSH_INTERACTIVE
6408 if (end_trigger == ';')
6409 inp->promptmode = 0; /* PS1 */
6411 pipe_list = parse_stream(NULL, inp, end_trigger);
6412 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6413 /* If we are in "big" script
6414 * (not in `cmd` or something similar)...
6416 if (pipe_list == ERR_PTR && end_trigger == ';') {
6417 /* Discard cached input (rest of line) */
6418 int ch = inp->last_char;
6419 while (ch != EOF && ch != '\n') {
6420 //bb_error_msg("Discarded:'%c'", ch);
6425 /* This stream isn't empty */
6429 if (!pipe_list && empty)
6430 G.last_exitcode = 0;
6433 debug_print_tree(pipe_list, 0);
6434 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6435 run_and_free_list(pipe_list);
6437 if (G_flag_return_in_progress == 1)
6442 static void parse_and_run_string(const char *s)
6444 struct in_str input;
6445 setup_string_in_str(&input, s);
6446 parse_and_run_stream(&input, '\0');
6449 static void parse_and_run_file(FILE *f)
6451 struct in_str input;
6452 setup_file_in_str(&input, f);
6453 parse_and_run_stream(&input, ';');
6456 #if ENABLE_HUSH_TICK
6457 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6462 char **to_free = NULL;
6466 pid = BB_MMU ? xfork() : xvfork();
6467 if (pid == 0) { /* child */
6468 disable_restore_tty_pgrp_on_exit();
6469 /* Process substitution is not considered to be usual
6470 * 'command execution'.
6471 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6478 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6479 close(channel[0]); /* NB: close _first_, then move fd! */
6480 xmove_fd(channel[1], 1);
6481 /* Prevent it from trying to handle ctrl-z etc */
6482 IF_HUSH_JOB(G.run_list_level = 1;)
6483 # if ENABLE_HUSH_TRAP
6484 /* Awful hack for `trap` or $(trap).
6486 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6487 * contains an example where "trap" is executed in a subshell:
6489 * save_traps=$(trap)
6491 * eval "$save_traps"
6493 * Standard does not say that "trap" in subshell shall print
6494 * parent shell's traps. It only says that its output
6495 * must have suitable form, but then, in the above example
6496 * (which is not supposed to be normative), it implies that.
6498 * bash (and probably other shell) does implement it
6499 * (traps are reset to defaults, but "trap" still shows them),
6500 * but as a result, "trap" logic is hopelessly messed up:
6503 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6504 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6505 * # true | trap <--- trap is in subshell - no output (ditto)
6506 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6507 * trap -- 'echo Ho' SIGWINCH
6508 * # echo `(trap)` <--- in subshell in subshell - output
6509 * trap -- 'echo Ho' SIGWINCH
6510 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6511 * trap -- 'echo Ho' SIGWINCH
6513 * The rules when to forget and when to not forget traps
6514 * get really complex and nonsensical.
6516 * Our solution: ONLY bare $(trap) or `trap` is special.
6518 s = skip_whitespace(s);
6519 if (is_prefixed_with(s, "trap")
6520 && skip_whitespace(s + 4)[0] == '\0'
6522 static const char *const argv[] = { NULL, NULL };
6523 builtin_trap((char**)argv);
6524 fflush_all(); /* important */
6529 reset_traps_to_defaults();
6530 parse_and_run_string(s);
6531 _exit(G.last_exitcode);
6533 /* We re-execute after vfork on NOMMU. This makes this script safe:
6534 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6535 * huge=`cat BIG` # was blocking here forever
6538 re_execute_shell(&to_free,
6548 # if ENABLE_HUSH_FAST
6550 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6551 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6552 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6554 enable_restore_tty_pgrp_on_exit();
6559 return remember_FILE(xfdopen_for_read(channel[0]));
6562 /* Return code is exit status of the process that is run. */
6563 static int process_command_subs(o_string *dest, const char *s)
6566 struct in_str pipe_str;
6568 int status, ch, eol_cnt;
6570 fp = generate_stream_from_string(s, &pid);
6572 /* Now send results of command back into original context */
6573 setup_file_in_str(&pipe_str, fp);
6575 while ((ch = i_getch(&pipe_str)) != EOF) {
6581 o_addchr(dest, '\n');
6584 o_addQchr(dest, ch);
6587 debug_printf("done reading from `cmd` pipe, closing it\n");
6588 fclose_and_forget(fp);
6589 /* We need to extract exitcode. Test case
6590 * "true; echo `sleep 1; false` $?"
6592 safe_waitpid(pid, &status, 0);
6593 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6594 return WEXITSTATUS(status);
6596 #endif /* ENABLE_HUSH_TICK */
6599 static void setup_heredoc(struct redir_struct *redir)
6601 struct fd_pair pair;
6604 /* the _body_ of heredoc (misleading field name) */
6605 const char *heredoc = redir->rd_filename;
6612 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6613 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6617 len = strlen(heredoc);
6619 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6621 xmove_fd(pair.rd, redir->rd_fd);
6623 /* Try writing without forking. Newer kernels have
6624 * dynamically growing pipes. Must use non-blocking write! */
6627 written = write(pair.wr, heredoc, len);
6638 ndelay_off(pair.wr);
6640 /* Okay, pipe buffer was not big enough */
6641 /* Note: we must not create a stray child (bastard? :)
6642 * for the unsuspecting parent process. Child creates a grandchild
6643 * and exits before parent execs the process which consumes heredoc
6644 * (that exec happens after we return from this function) */
6651 disable_restore_tty_pgrp_on_exit();
6652 pid = BB_MMU ? xfork() : xvfork();
6656 close(redir->rd_fd); /* read side of the pipe */
6658 full_write(pair.wr, heredoc, len); /* may loop or block */
6661 /* Delegate blocking writes to another process */
6662 xmove_fd(pair.wr, STDOUT_FILENO);
6663 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6667 #if ENABLE_HUSH_FAST
6669 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6671 enable_restore_tty_pgrp_on_exit();
6677 wait(NULL); /* wait till child has died */
6683 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6684 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6687 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6689 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6690 sq[i].orig_fd = orig;
6691 sq[i].moved_to = moved;
6692 sq[i+1].orig_fd = -1; /* end marker */
6696 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6701 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6702 /* If we collide with an already moved fd... */
6703 if (fd == sq[i].moved_to) {
6704 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6705 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6706 if (sq[i].moved_to < 0) /* what? */
6710 if (fd == sq[i].orig_fd) {
6711 /* Example: echo Hello >/dev/null 1>&2 */
6712 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6717 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6718 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6719 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6720 if (moved_to < 0 && errno != EBADF)
6722 return append_squirrel(sq, i, fd, moved_to);
6725 static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
6729 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6730 /* If we collide with an already moved fd... */
6731 if (fd == sq[i].orig_fd) {
6733 * "echo 3>FILE 3>&- 3>FILE"
6734 * "echo 3>&- 3>FILE"
6735 * No need for last redirect to insert
6736 * another "need to close 3" indicator.
6738 debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
6743 debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
6744 return append_squirrel(sq, i, fd, -1);
6747 /* fd: redirect wants this fd to be used (e.g. 3>file).
6748 * Move all conflicting internally used fds,
6749 * and remember them so that we can restore them later.
6751 static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6753 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6756 #if ENABLE_HUSH_INTERACTIVE
6757 if (fd == G.interactive_fd) {
6758 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
6759 G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
6760 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6761 return 1; /* "we closed fd" */
6764 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6765 * (1) Redirect in a forked child. No need to save FILEs' fds,
6766 * we aren't going to use them anymore, ok to trash.
6767 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6768 * but how are we doing to restore them?
6769 * "fileno(fd) = new_fd" can't be done.
6774 /* If this one of script's fds? */
6775 if (save_FILEs_on_redirect(fd, avoid_fd))
6776 return 1; /* yes. "we closed fd" */
6778 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6779 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6780 return 0; /* "we did not close fd" */
6783 static void restore_redirects(struct squirrel *sq)
6787 for (i = 0; sq[i].orig_fd >= 0; i++) {
6788 if (sq[i].moved_to >= 0) {
6789 /* We simply die on error */
6790 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6791 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6793 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6794 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6795 close(sq[i].orig_fd);
6801 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6803 restore_redirected_FILEs();
6806 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
6807 static void close_saved_fds_and_FILE_fds(void)
6809 if (G_interactive_fd)
6810 close(G_interactive_fd);
6811 close_all_FILE_list();
6815 static int internally_opened_fd(int fd, struct squirrel *sq)
6819 #if ENABLE_HUSH_INTERACTIVE
6820 if (fd == G.interactive_fd)
6823 /* If this one of script's fds? */
6824 if (fd_in_FILEs(fd))
6827 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6828 if (fd == sq[i].moved_to)
6834 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6835 * and stderr if they are redirected. */
6836 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6838 struct redir_struct *redir;
6840 for (redir = prog->redirects; redir; redir = redir->next) {
6844 if (redir->rd_type == REDIRECT_HEREDOC2) {
6845 /* "rd_fd<<HERE" case */
6846 save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6847 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6849 debug_printf_parse("set heredoc '%s'\n",
6850 redir->rd_filename);
6851 setup_heredoc(redir);
6855 if (redir->rd_dup == REDIRFD_TO_FILE) {
6856 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6860 if (redir->rd_filename == NULL) {
6863 * "cmd >" (no filename)
6864 * "cmd > <file" (2nd redirect starts too early)
6866 die_if_script("syntax error: %s", "invalid redirect");
6869 mode = redir_table[redir->rd_type].mode;
6870 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6871 newfd = open_or_warn(p, mode);
6874 /* Error message from open_or_warn can be lost
6875 * if stderr has been redirected, but bash
6876 * and ash both lose it as well
6877 * (though zsh doesn't!)
6881 if (newfd == redir->rd_fd && sqp) {
6882 /* open() gave us precisely the fd we wanted.
6883 * This means that this fd was not busy
6884 * (not opened to anywhere).
6885 * Remember to close it on restore:
6887 *sqp = add_squirrel_closed(*sqp, newfd);
6888 debug_printf_redir("redir to previously closed fd %d\n", newfd);
6891 /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
6892 newfd = redir->rd_dup;
6895 if (newfd == redir->rd_fd)
6898 /* if "N>FILE": move newfd to redir->rd_fd */
6899 /* if "N>&M": dup newfd to redir->rd_fd */
6900 /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
6902 closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
6903 if (newfd == REDIRFD_CLOSE) {
6904 /* "N>&-" means "close me" */
6906 /* ^^^ optimization: saving may already
6907 * have closed it. If not... */
6908 close(redir->rd_fd);
6910 /* Sometimes we do another close on restore, getting EBADF.
6911 * Consider "echo 3>FILE 3>&-"
6912 * first redirect remembers "need to close 3",
6913 * and second redirect closes 3! Restore code then closes 3 again.
6916 /* if newfd is a script fd or saved fd, simulate EBADF */
6917 if (internally_opened_fd(newfd, sqp ? *sqp : NULL)) {
6919 //bb_perror_msg_and_die("can't duplicate file descriptor");
6920 newfd = -1; /* same effect as code above */
6922 xdup2(newfd, redir->rd_fd);
6923 if (redir->rd_dup == REDIRFD_TO_FILE)
6924 /* "rd_fd > FILE" */
6926 /* else: "rd_fd > rd_dup" */
6932 static char *find_in_path(const char *arg)
6935 const char *PATH = get_local_var_value("PATH");
6941 const char *end = strchrnul(PATH, ':');
6942 int sz = end - PATH; /* must be int! */
6946 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6948 /* We have xxx::yyyy in $PATH,
6949 * it means "use current dir" */
6952 if (access(ret, F_OK) == 0)
6965 static const struct built_in_command *find_builtin_helper(const char *name,
6966 const struct built_in_command *x,
6967 const struct built_in_command *end)
6970 if (strcmp(name, x->b_cmd) != 0) {
6974 debug_printf_exec("found builtin '%s'\n", name);
6979 static const struct built_in_command *find_builtin1(const char *name)
6981 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6983 static const struct built_in_command *find_builtin(const char *name)
6985 const struct built_in_command *x = find_builtin1(name);
6988 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6991 #if ENABLE_HUSH_FUNCTIONS
6992 static struct function **find_function_slot(const char *name)
6994 struct function **funcpp = &G.top_func;
6996 if (strcmp(name, (*funcpp)->name) == 0) {
6999 funcpp = &(*funcpp)->next;
7004 static const struct function *find_function(const char *name)
7006 const struct function *funcp = *find_function_slot(name);
7008 debug_printf_exec("found function '%s'\n", name);
7012 /* Note: takes ownership on name ptr */
7013 static struct function *new_function(char *name)
7015 struct function **funcpp = find_function_slot(name);
7016 struct function *funcp = *funcpp;
7018 if (funcp != NULL) {
7019 struct command *cmd = funcp->parent_cmd;
7020 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
7022 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
7024 /* Note: if !funcp->body, do not free body_as_string!
7025 * This is a special case of "-F name body" function:
7026 * body_as_string was not malloced! */
7028 free_pipe_list(funcp->body);
7030 free(funcp->body_as_string);
7034 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
7035 cmd->argv[0] = funcp->name;
7036 cmd->group = funcp->body;
7038 cmd->group_as_string = funcp->body_as_string;
7042 debug_printf_exec("remembering new function '%s'\n", name);
7043 funcp = *funcpp = xzalloc(sizeof(*funcp));
7044 /*funcp->next = NULL;*/
7051 # if ENABLE_HUSH_UNSET
7052 static void unset_func(const char *name)
7054 struct function **funcpp = find_function_slot(name);
7055 struct function *funcp = *funcpp;
7057 if (funcp != NULL) {
7058 debug_printf_exec("freeing function '%s'\n", funcp->name);
7059 *funcpp = funcp->next;
7060 /* funcp is unlinked now, deleting it.
7061 * Note: if !funcp->body, the function was created by
7062 * "-F name body", do not free ->body_as_string
7063 * and ->name as they were not malloced. */
7065 free_pipe_list(funcp->body);
7068 free(funcp->body_as_string);
7077 #define exec_function(to_free, funcp, argv) \
7078 exec_function(funcp, argv)
7080 static void exec_function(char ***to_free,
7081 const struct function *funcp,
7082 char **argv) NORETURN;
7083 static void exec_function(char ***to_free,
7084 const struct function *funcp,
7090 argv[0] = G.global_argv[0];
7091 G.global_argv = argv;
7092 G.global_argc = n = 1 + string_array_len(argv + 1);
7094 // Example when we are here: "cmd | func"
7095 // func will run with saved-redirect fds open.
7096 // $ f() { echo /proc/self/fd/*; }
7098 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
7099 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
7102 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
7103 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
7104 // They are CLOEXEC so external programs won't see them, but
7105 // for "more correctness" we might want to close those extra fds here:
7106 //? close_saved_fds_and_FILE_fds();
7108 /* "we are in function, ok to use return" */
7109 G_flag_return_in_progress = -1;
7110 IF_HUSH_LOCAL(G.func_nest_level++;)
7112 /* On MMU, funcp->body is always non-NULL */
7113 n = run_list(funcp->body);
7117 //? close_saved_fds_and_FILE_fds();
7119 //TODO: check whether "true | func_with_return" works
7121 re_execute_shell(to_free,
7122 funcp->body_as_string,
7129 static int run_function(const struct function *funcp, char **argv)
7135 save_and_replace_G_args(&sv, argv);
7137 /* "we are in function, ok to use return" */
7138 sv_flg = G_flag_return_in_progress;
7139 G_flag_return_in_progress = -1;
7140 IF_HUSH_LOCAL(G.func_nest_level++;)
7142 /* On MMU, funcp->body is always non-NULL */
7145 /* Function defined by -F */
7146 parse_and_run_string(funcp->body_as_string);
7147 rc = G.last_exitcode;
7151 rc = run_list(funcp->body);
7154 # if ENABLE_HUSH_LOCAL
7156 struct variable *var;
7157 struct variable **var_pp;
7159 var_pp = &G.top_var;
7160 while ((var = *var_pp) != NULL) {
7161 if (var->func_nest_level < G.func_nest_level) {
7162 var_pp = &var->next;
7166 if (var->flg_export)
7167 bb_unsetenv(var->varstr);
7168 /* Remove from global list */
7169 *var_pp = var->next;
7175 G.func_nest_level--;
7178 G_flag_return_in_progress = sv_flg;
7180 restore_G_args(&sv, argv);
7184 #endif /* ENABLE_HUSH_FUNCTIONS */
7188 #define exec_builtin(to_free, x, argv) \
7189 exec_builtin(x, argv)
7191 #define exec_builtin(to_free, x, argv) \
7192 exec_builtin(to_free, argv)
7194 static void exec_builtin(char ***to_free,
7195 const struct built_in_command *x,
7196 char **argv) NORETURN;
7197 static void exec_builtin(char ***to_free,
7198 const struct built_in_command *x,
7204 //? close_saved_fds_and_FILE_fds();
7205 rcode = x->b_function(argv);
7210 /* On NOMMU, we must never block!
7211 * Example: { sleep 99 | read line; } & echo Ok
7213 re_execute_shell(to_free,
7222 static void execvp_or_die(char **argv) NORETURN;
7223 static void execvp_or_die(char **argv)
7226 debug_printf_exec("execing '%s'\n", argv[0]);
7227 /* Don't propagate SIG_IGN to the child */
7228 if (SPECIAL_JOBSTOP_SIGS != 0)
7229 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7230 execvp(argv[0], argv);
7232 if (errno == EACCES) e = 126;
7233 if (errno == ENOENT) e = 127;
7234 bb_perror_msg("can't execute '%s'", argv[0]);
7238 #if ENABLE_HUSH_MODE_X
7239 static void dump_cmd_in_x_mode(char **argv)
7241 if (G_x_mode && argv) {
7242 /* We want to output the line in one write op */
7250 len += strlen(argv[n++]) + 1;
7256 p += sprintf(p, " %s", argv[n++]);
7264 # define dump_cmd_in_x_mode(argv) ((void)0)
7268 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7269 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7270 #define pseudo_exec(nommu_save, command, argv_expanded) \
7271 pseudo_exec(command, argv_expanded)
7274 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7276 * Don't exit() here. If you don't exec, use _exit instead.
7277 * The at_exit handlers apparently confuse the calling process,
7278 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7280 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7281 char **argv, int assignment_cnt,
7282 char **argv_expanded) NORETURN;
7283 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7284 char **argv, int assignment_cnt,
7285 char **argv_expanded)
7289 new_env = expand_assignments(argv, assignment_cnt);
7290 dump_cmd_in_x_mode(new_env);
7292 if (!argv[assignment_cnt]) {
7293 /* Case when we are here: ... | var=val | ...
7294 * (note that we do not exit early, i.e., do not optimize out
7295 * expand_assignments(): think about ... | var=`sleep 1` | ...
7297 free_strings(new_env);
7298 _exit(EXIT_SUCCESS);
7302 set_vars_and_save_old(new_env);
7303 free(new_env); /* optional */
7304 /* we can also destroy set_vars_and_save_old's return value,
7307 nommu_save->new_env = new_env;
7308 nommu_save->old_vars = set_vars_and_save_old(new_env);
7311 if (argv_expanded) {
7312 argv = argv_expanded;
7314 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7316 nommu_save->argv = argv;
7319 dump_cmd_in_x_mode(argv);
7321 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7322 if (strchr(argv[0], '/') != NULL)
7326 #if ENABLE_HUSH_FUNCTIONS
7327 /* Check if the command matches any functions (this goes before bltins) */
7329 const struct function *funcp = find_function(argv[0]);
7331 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7336 /* Check if the command matches any of the builtins.
7337 * Depending on context, this might be redundant. But it's
7338 * easier to waste a few CPU cycles than it is to figure out
7339 * if this is one of those cases.
7342 /* On NOMMU, it is more expensive to re-execute shell
7343 * just in order to run echo or test builtin.
7344 * It's better to skip it here and run corresponding
7345 * non-builtin later. */
7346 const struct built_in_command *x;
7347 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7349 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7353 #if ENABLE_FEATURE_SH_STANDALONE
7354 /* Check if the command matches any busybox applets */
7356 int a = find_applet_by_name(argv[0]);
7358 # if BB_MMU /* see above why on NOMMU it is not allowed */
7359 if (APPLET_IS_NOEXEC(a)) {
7360 /* Do not leak open fds from opened script files etc.
7361 * Testcase: interactive "ls -l /proc/self/fd"
7362 * should not show tty fd open.
7364 close_saved_fds_and_FILE_fds();
7365 //FIXME: should also close saved redir fds
7366 /* Without this, "rm -i FILE" can't be ^C'ed: */
7367 switch_off_special_sigs(G.special_sig_mask);
7368 debug_printf_exec("running applet '%s'\n", argv[0]);
7369 run_applet_no_and_exit(a, argv[0], argv);
7372 /* Re-exec ourselves */
7373 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7374 /* Don't propagate SIG_IGN to the child */
7375 if (SPECIAL_JOBSTOP_SIGS != 0)
7376 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7377 execv(bb_busybox_exec_path, argv);
7378 /* If they called chroot or otherwise made the binary no longer
7379 * executable, fall through */
7384 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7387 execvp_or_die(argv);
7390 /* Called after [v]fork() in run_pipe
7392 static void pseudo_exec(nommu_save_t *nommu_save,
7393 struct command *command,
7394 char **argv_expanded) NORETURN;
7395 static void pseudo_exec(nommu_save_t *nommu_save,
7396 struct command *command,
7397 char **argv_expanded)
7399 if (command->argv) {
7400 pseudo_exec_argv(nommu_save, command->argv,
7401 command->assignment_cnt, argv_expanded);
7404 if (command->group) {
7405 /* Cases when we are here:
7408 * ... | ( list ) | ...
7409 * ... | { list } | ...
7413 debug_printf_exec("pseudo_exec: run_list\n");
7414 reset_traps_to_defaults();
7415 rcode = run_list(command->group);
7416 /* OK to leak memory by not calling free_pipe_list,
7417 * since this process is about to exit */
7420 re_execute_shell(&nommu_save->argv_from_re_execing,
7421 command->group_as_string,
7428 /* Case when we are here: ... | >file */
7429 debug_printf_exec("pseudo_exec'ed null command\n");
7430 _exit(EXIT_SUCCESS);
7434 static const char *get_cmdtext(struct pipe *pi)
7440 /* This is subtle. ->cmdtext is created only on first backgrounding.
7441 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7442 * On subsequent bg argv is trashed, but we won't use it */
7446 argv = pi->cmds[0].argv;
7448 pi->cmdtext = xzalloc(1);
7453 len += strlen(*argv) + 1;
7457 argv = pi->cmds[0].argv;
7459 p = stpcpy(p, *argv);
7466 static void remove_job_from_table(struct pipe *pi)
7468 struct pipe *prev_pipe;
7470 if (pi == G.job_list) {
7471 G.job_list = pi->next;
7473 prev_pipe = G.job_list;
7474 while (prev_pipe->next != pi)
7475 prev_pipe = prev_pipe->next;
7476 prev_pipe->next = pi->next;
7480 G.last_jobid = G.job_list->jobid;
7483 static void delete_finished_job(struct pipe *pi)
7485 remove_job_from_table(pi);
7489 static void clean_up_last_dead_job(void)
7491 if (G.job_list && !G.job_list->alive_cmds)
7492 delete_finished_job(G.job_list);
7495 static void insert_job_into_table(struct pipe *pi)
7497 struct pipe *job, **jobp;
7500 clean_up_last_dead_job();
7502 /* Find the end of the list, and find next job ID to use */
7505 while ((job = *jobp) != NULL) {
7512 /* Create a new job struct at the end */
7513 job = *jobp = xmemdup(pi, sizeof(*pi));
7515 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7516 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7517 for (i = 0; i < pi->num_cmds; i++) {
7518 job->cmds[i].pid = pi->cmds[i].pid;
7519 /* all other fields are not used and stay zero */
7521 job->cmdtext = xstrdup(get_cmdtext(pi));
7523 if (G_interactive_fd)
7524 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7525 G.last_jobid = job->jobid;
7529 static int job_exited_or_stopped(struct pipe *pi)
7533 if (pi->alive_cmds != pi->stopped_cmds)
7536 /* All processes in fg pipe have exited or stopped */
7540 rcode = pi->cmds[i].cmd_exitcode;
7541 /* usually last process gives overall exitstatus,
7542 * but with "set -o pipefail", last *failed* process does */
7543 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7546 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7550 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7557 dead = WIFEXITED(status) || WIFSIGNALED(status);
7560 if (WIFSTOPPED(status))
7561 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7562 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7563 if (WIFSIGNALED(status))
7564 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7565 childpid, WTERMSIG(status), WEXITSTATUS(status));
7566 if (WIFEXITED(status))
7567 debug_printf_jobs("pid %d exited, exitcode %d\n",
7568 childpid, WEXITSTATUS(status));
7570 /* Were we asked to wait for a fg pipe? */
7572 i = fg_pipe->num_cmds;
7577 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7578 if (fg_pipe->cmds[i].pid != childpid)
7582 fg_pipe->cmds[i].pid = 0;
7583 fg_pipe->alive_cmds--;
7584 ex = WEXITSTATUS(status);
7585 /* bash prints killer signal's name for *last*
7586 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7587 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7589 if (WIFSIGNALED(status)) {
7590 int sig = WTERMSIG(status);
7591 if (i == fg_pipe->num_cmds-1)
7592 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7593 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7594 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7595 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7596 * Maybe we need to use sig | 128? */
7599 fg_pipe->cmds[i].cmd_exitcode = ex;
7601 fg_pipe->stopped_cmds++;
7603 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7604 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7605 rcode = job_exited_or_stopped(fg_pipe);
7607 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7608 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7609 * and "killall -STOP cat" */
7610 if (G_interactive_fd) {
7612 if (fg_pipe->alive_cmds != 0)
7613 insert_job_into_table(fg_pipe);
7617 if (fg_pipe->alive_cmds == 0)
7620 /* There are still running processes in the fg_pipe */
7623 /* It wasn't in fg_pipe, look for process in bg pipes */
7627 /* We were asked to wait for bg or orphaned children */
7628 /* No need to remember exitcode in this case */
7629 for (pi = G.job_list; pi; pi = pi->next) {
7630 for (i = 0; i < pi->num_cmds; i++) {
7631 if (pi->cmds[i].pid == childpid)
7632 goto found_pi_and_prognum;
7635 /* Happens when shell is used as init process (init=/bin/sh) */
7636 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7637 return -1; /* this wasn't a process from fg_pipe */
7639 found_pi_and_prognum:
7642 int rcode = WEXITSTATUS(status);
7643 if (WIFSIGNALED(status))
7644 rcode = 128 + WTERMSIG(status);
7645 pi->cmds[i].cmd_exitcode = rcode;
7646 if (G.last_bg_pid == pi->cmds[i].pid)
7647 G.last_bg_pid_exitcode = rcode;
7648 pi->cmds[i].pid = 0;
7650 if (!pi->alive_cmds) {
7651 if (G_interactive_fd) {
7652 printf(JOB_STATUS_FORMAT, pi->jobid,
7653 "Done", pi->cmdtext);
7654 delete_finished_job(pi);
7657 * bash deletes finished jobs from job table only in interactive mode,
7658 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7659 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7660 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7661 * We only retain one "dead" job, if it's the single job on the list.
7662 * This covers most of real-world scenarios where this is useful.
7664 if (pi != G.job_list)
7665 delete_finished_job(pi);
7673 return -1; /* this wasn't a process from fg_pipe */
7676 /* Check to see if any processes have exited -- if they have,
7677 * figure out why and see if a job has completed.
7679 * If non-NULL fg_pipe: wait for its completion or stop.
7680 * Return its exitcode or zero if stopped.
7682 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7683 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7684 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7685 * or 0 if no children changed status.
7687 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7688 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7689 * or 0 if no children changed status.
7691 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7697 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7699 attributes = WUNTRACED;
7700 if (fg_pipe == NULL)
7701 attributes |= WNOHANG;
7704 #if ENABLE_HUSH_FAST
7705 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7706 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7707 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7708 /* There was neither fork nor SIGCHLD since last waitpid */
7709 /* Avoid doing waitpid syscall if possible */
7710 if (!G.we_have_children) {
7714 if (fg_pipe == NULL) { /* is WNOHANG set? */
7715 /* We have children, but they did not exit
7716 * or stop yet (we saw no SIGCHLD) */
7719 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7723 /* Do we do this right?
7724 * bash-3.00# sleep 20 | false
7726 * [3]+ Stopped sleep 20 | false
7727 * bash-3.00# echo $?
7728 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7729 * [hush 1.14.0: yes we do it right]
7733 #if ENABLE_HUSH_FAST
7735 i = G.count_SIGCHLD;
7737 childpid = waitpid(-1, &status, attributes);
7738 if (childpid <= 0) {
7739 if (childpid && errno != ECHILD)
7740 bb_perror_msg("waitpid");
7741 #if ENABLE_HUSH_FAST
7742 else { /* Until next SIGCHLD, waitpid's are useless */
7743 G.we_have_children = (childpid == 0);
7744 G.handled_SIGCHLD = i;
7745 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7748 /* ECHILD (no children), or 0 (no change in children status) */
7752 rcode = process_wait_result(fg_pipe, childpid, status);
7754 /* fg_pipe exited or stopped */
7757 if (childpid == waitfor_pid) {
7758 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7759 rcode = WEXITSTATUS(status);
7760 if (WIFSIGNALED(status))
7761 rcode = 128 + WTERMSIG(status);
7762 if (WIFSTOPPED(status))
7763 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7764 rcode = 128 + WSTOPSIG(status);
7766 break; /* "wait PID" called us, give it exitcode+1 */
7768 /* This wasn't one of our processes, or */
7769 /* fg_pipe still has running processes, do waitpid again */
7770 } /* while (waitpid succeeds)... */
7776 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7779 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7780 if (G_saved_tty_pgrp) {
7781 /* Job finished, move the shell to the foreground */
7782 p = getpgrp(); /* our process group id */
7783 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7784 tcsetpgrp(G_interactive_fd, p);
7790 /* Start all the jobs, but don't wait for anything to finish.
7793 * Return code is normally -1, when the caller has to wait for children
7794 * to finish to determine the exit status of the pipe. If the pipe
7795 * is a simple builtin command, however, the action is done by the
7796 * time run_pipe returns, and the exit code is provided as the
7799 * Returns -1 only if started some children. IOW: we have to
7800 * mask out retvals of builtins etc with 0xff!
7802 * The only case when we do not need to [v]fork is when the pipe
7803 * is single, non-backgrounded, non-subshell command. Examples:
7804 * cmd ; ... { list } ; ...
7805 * cmd && ... { list } && ...
7806 * cmd || ... { list } || ...
7807 * If it is, then we can run cmd as a builtin, NOFORK,
7808 * or (if SH_STANDALONE) an applet, and we can run the { list }
7809 * with run_list. If it isn't one of these, we fork and exec cmd.
7811 * Cases when we must fork:
7812 * non-single: cmd | cmd
7813 * backgrounded: cmd & { list } &
7814 * subshell: ( list ) [&]
7816 #if !ENABLE_HUSH_MODE_X
7817 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7818 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7820 static int redirect_and_varexp_helper(char ***new_env_p,
7821 struct variable **old_vars_p,
7822 struct command *command,
7823 struct squirrel **sqp,
7824 char **argv_expanded)
7826 /* setup_redirects acts on file descriptors, not FILEs.
7827 * This is perfect for work that comes after exec().
7828 * Is it really safe for inline use? Experimentally,
7829 * things seem to work. */
7830 int rcode = setup_redirects(command, sqp);
7832 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7833 *new_env_p = new_env;
7834 dump_cmd_in_x_mode(new_env);
7835 dump_cmd_in_x_mode(argv_expanded);
7837 *old_vars_p = set_vars_and_save_old(new_env);
7841 static NOINLINE int run_pipe(struct pipe *pi)
7843 static const char *const null_ptr = NULL;
7847 struct command *command;
7848 char **argv_expanded;
7850 struct squirrel *squirrel = NULL;
7853 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7856 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7857 * Result should be 3 lines: q w e, qwe, q w e
7859 G.ifs = get_local_var_value("IFS");
7863 IF_HUSH_JOB(pi->pgrp = -1;)
7864 pi->stopped_cmds = 0;
7865 command = &pi->cmds[0];
7866 argv_expanded = NULL;
7868 if (pi->num_cmds != 1
7869 || pi->followup == PIPE_BG
7870 || command->cmd_type == CMD_SUBSHELL
7877 debug_printf_exec(": group:%p argv:'%s'\n",
7878 command->group, command->argv ? command->argv[0] : "NONE");
7880 if (command->group) {
7881 #if ENABLE_HUSH_FUNCTIONS
7882 if (command->cmd_type == CMD_FUNCDEF) {
7883 /* "executing" func () { list } */
7884 struct function *funcp;
7886 funcp = new_function(command->argv[0]);
7887 /* funcp->name is already set to argv[0] */
7888 funcp->body = command->group;
7890 funcp->body_as_string = command->group_as_string;
7891 command->group_as_string = NULL;
7893 command->group = NULL;
7894 command->argv[0] = NULL;
7895 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7896 funcp->parent_cmd = command;
7897 command->child_func = funcp;
7899 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7901 return EXIT_SUCCESS;
7905 debug_printf("non-subshell group\n");
7906 rcode = 1; /* exitcode if redir failed */
7907 if (setup_redirects(command, &squirrel) == 0) {
7908 debug_printf_exec(": run_list\n");
7909 rcode = run_list(command->group) & 0xff;
7911 restore_redirects(squirrel);
7912 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7914 debug_printf_exec("run_pipe: return %d\n", rcode);
7918 argv = command->argv ? command->argv : (char **) &null_ptr;
7920 const struct built_in_command *x;
7921 #if ENABLE_HUSH_FUNCTIONS
7922 const struct function *funcp;
7926 char **new_env = NULL;
7927 struct variable *old_vars = NULL;
7929 if (argv[command->assignment_cnt] == NULL) {
7930 /* Assignments, but no command */
7931 /* Ensure redirects take effect (that is, create files).
7932 * Try "a=t >file" */
7933 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7934 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7935 /* Set shell variables */
7939 if (set_local_var(*argv, /*flag:*/ 0)) {
7940 /* assignment to readonly var / putenv error? */
7946 /* Redirect error sets $? to 1. Otherwise,
7947 * if evaluating assignment value set $?, retain it.
7948 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7950 rcode = G.last_exitcode;
7951 /* Exit, _skipping_ variable restoring code: */
7952 goto clean_up_and_ret0;
7954 #else /* Older, bigger, but more correct code */
7956 rcode = setup_redirects(command, &squirrel);
7957 restore_redirects(squirrel);
7958 /* Set shell variables */
7960 bb_putchar_stderr('+');
7962 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7964 fprintf(stderr, " %s", p);
7965 debug_printf_exec("set shell var:'%s'->'%s'\n",
7967 if (set_local_var(p, /*flag:*/ 0)) {
7968 /* assignment to readonly var / putenv error? */
7974 bb_putchar_stderr('\n');
7975 /* Redirect error sets $? to 1. Otherwise,
7976 * if evaluating assignment value set $?, retain it.
7977 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7979 rcode = G.last_exitcode;
7980 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7982 debug_printf_exec("run_pipe: return %d\n", rcode);
7987 /* Expand the rest into (possibly) many strings each */
7989 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7990 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7994 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7997 /* if someone gives us an empty string: `cmd with empty output` */
7998 if (!argv_expanded[0]) {
7999 free(argv_expanded);
8001 return G.last_exitcode;
8004 #if ENABLE_HUSH_FUNCTIONS
8005 /* Check if argv[0] matches any functions (this goes before bltins) */
8006 funcp = find_function(argv_expanded[0]);
8010 x = find_builtin(argv_expanded[0]);
8013 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
8014 debug_printf("exec with redirects only\n");
8015 rcode = setup_redirects(command, NULL);
8016 /* rcode=1 can be if redir file can't be opened */
8017 goto clean_up_and_ret1;
8020 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8023 debug_printf_exec(": builtin '%s' '%s'...\n",
8024 x->b_cmd, argv_expanded[1]);
8026 rcode = x->b_function(argv_expanded) & 0xff;
8029 #if ENABLE_HUSH_FUNCTIONS
8031 # if ENABLE_HUSH_LOCAL
8032 struct variable **sv;
8033 sv = G.shadowed_vars_pp;
8034 G.shadowed_vars_pp = &old_vars;
8036 debug_printf_exec(": function '%s' '%s'...\n",
8037 funcp->name, argv_expanded[1]);
8038 rcode = run_function(funcp, argv_expanded) & 0xff;
8039 # if ENABLE_HUSH_LOCAL
8040 G.shadowed_vars_pp = sv;
8046 unset_vars(new_env);
8048 /* clean_up_and_ret0: */
8049 restore_redirects(squirrel);
8051 * Try "usleep 99999999" + ^C + "echo $?"
8052 * with FEATURE_SH_NOFORK=y.
8055 /* It was builtin or nofork.
8056 * if this would be a real fork/execed program,
8057 * it should have died if a fatal sig was received.
8058 * But OTOH, there was no separate process,
8059 * the sig was sent to _shell_, not to non-existing
8061 * Let's just handle ^C only, this one is obvious:
8062 * we aren't ok with exitcode 0 when ^C was pressed
8063 * during builtin/nofork.
8065 if (sigismember(&G.pending_set, SIGINT))
8066 rcode = 128 + SIGINT;
8069 free(argv_expanded);
8070 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8072 debug_printf_exec("run_pipe return %d\n", rcode);
8076 if (ENABLE_FEATURE_SH_NOFORK) {
8077 int n = find_applet_by_name(argv_expanded[0]);
8078 if (n >= 0 && APPLET_IS_NOFORK(n)) {
8079 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8081 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
8082 argv_expanded[0], argv_expanded[1]);
8084 * Note: signals (^C) can't interrupt here.
8085 * We remember them and they will be acted upon
8086 * after applet returns.
8087 * This makes applets which can run for a long time
8088 * and/or wait for user input ineligible for NOFORK:
8089 * for example, "yes" or "rm" (rm -i waits for input).
8091 rcode = run_nofork_applet(n, argv_expanded);
8093 goto clean_up_and_ret;
8096 /* It is neither builtin nor applet. We must fork. */
8100 /* NB: argv_expanded may already be created, and that
8101 * might include `cmd` runs! Do not rerun it! We *must*
8102 * use argv_expanded if it's non-NULL */
8104 /* Going to fork a child per each pipe member */
8109 while (cmd_no < pi->num_cmds) {
8110 struct fd_pair pipefds;
8112 volatile nommu_save_t nommu_save;
8113 nommu_save.new_env = NULL;
8114 nommu_save.old_vars = NULL;
8115 nommu_save.argv = NULL;
8116 nommu_save.argv_from_re_execing = NULL;
8118 command = &pi->cmds[cmd_no];
8120 if (command->argv) {
8121 debug_printf_exec(": pipe member '%s' '%s'...\n",
8122 command->argv[0], command->argv[1]);
8124 debug_printf_exec(": pipe member with no argv\n");
8127 /* pipes are inserted between pairs of commands */
8130 if (cmd_no < pi->num_cmds)
8131 xpiped_pair(pipefds);
8133 command->pid = BB_MMU ? fork() : vfork();
8134 if (!command->pid) { /* child */
8136 disable_restore_tty_pgrp_on_exit();
8137 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8139 /* Every child adds itself to new process group
8140 * with pgid == pid_of_first_child_in_pipe */
8141 if (G.run_list_level == 1 && G_interactive_fd) {
8144 if (pgrp < 0) /* true for 1st process only */
8146 if (setpgid(0, pgrp) == 0
8147 && pi->followup != PIPE_BG
8148 && G_saved_tty_pgrp /* we have ctty */
8150 /* We do it in *every* child, not just first,
8152 tcsetpgrp(G_interactive_fd, pgrp);
8156 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8157 /* 1st cmd in backgrounded pipe
8158 * should have its stdin /dev/null'ed */
8160 if (open(bb_dev_null, O_RDONLY))
8161 xopen("/", O_RDONLY);
8163 xmove_fd(next_infd, 0);
8165 xmove_fd(pipefds.wr, 1);
8168 /* Like bash, explicit redirects override pipes,
8169 * and the pipe fd (fd#1) is available for dup'ing:
8170 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8171 * of cmd1 goes into pipe.
8173 if (setup_redirects(command, NULL)) {
8174 /* Happens when redir file can't be opened:
8175 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8177 * hush: can't open '/qwe/rty': No such file or directory
8179 * (echo BAR is not executed, it hits _exit(1) below)
8184 /* Stores to nommu_save list of env vars putenv'ed
8185 * (NOMMU, on MMU we don't need that) */
8186 /* cast away volatility... */
8187 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8188 /* pseudo_exec() does not return */
8191 /* parent or error */
8192 #if ENABLE_HUSH_FAST
8194 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8196 enable_restore_tty_pgrp_on_exit();
8198 /* Clean up after vforked child */
8199 free(nommu_save.argv);
8200 free(nommu_save.argv_from_re_execing);
8201 unset_vars(nommu_save.new_env);
8202 add_vars(nommu_save.old_vars);
8204 free(argv_expanded);
8205 argv_expanded = NULL;
8206 if (command->pid < 0) { /* [v]fork failed */
8207 /* Clearly indicate, was it fork or vfork */
8208 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8212 /* Second and next children need to know pid of first one */
8214 pi->pgrp = command->pid;
8220 if (cmd_no < pi->num_cmds)
8222 /* Pass read (output) pipe end to next iteration */
8223 next_infd = pipefds.rd;
8226 if (!pi->alive_cmds) {
8228 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8233 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8237 /* NB: called by pseudo_exec, and therefore must not modify any
8238 * global data until exec/_exit (we can be a child after vfork!) */
8239 static int run_list(struct pipe *pi)
8241 #if ENABLE_HUSH_CASE
8242 char *case_word = NULL;
8244 #if ENABLE_HUSH_LOOPS
8245 struct pipe *loop_top = NULL;
8246 char **for_lcur = NULL;
8247 char **for_list = NULL;
8249 smallint last_followup;
8251 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8252 smalluint cond_code = 0;
8254 enum { cond_code = 0 };
8257 smallint rword; /* RES_foo */
8258 smallint last_rword; /* ditto */
8261 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8264 #if ENABLE_HUSH_LOOPS
8265 /* Check syntax for "for" */
8268 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8269 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8271 /* current word is FOR or IN (BOLD in comments below) */
8272 if (cpipe->next == NULL) {
8273 syntax_error("malformed for");
8275 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8278 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8279 if (cpipe->next->res_word == RES_DO)
8281 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8282 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8283 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8285 syntax_error("malformed for");
8287 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8294 /* Past this point, all code paths should jump to ret: label
8295 * in order to return, no direct "return" statements please.
8296 * This helps to ensure that no memory is leaked. */
8304 last_rword = RES_XXXX;
8306 last_followup = PIPE_SEQ;
8307 rcode = G.last_exitcode;
8309 /* Go through list of pipes, (maybe) executing them. */
8310 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8312 int sv_errexit_depth;
8316 if (G_flag_return_in_progress == 1)
8319 IF_HAS_KEYWORDS(rword = pi->res_word;)
8320 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8321 rword, cond_code, last_rword);
8323 sv_errexit_depth = G.errexit_depth;
8324 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8325 pi->followup != PIPE_SEQ
8329 #if ENABLE_HUSH_LOOPS
8330 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8331 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8333 /* start of a loop: remember where loop starts */
8338 /* Still in the same "if...", "then..." or "do..." branch? */
8339 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8340 if ((rcode == 0 && last_followup == PIPE_OR)
8341 || (rcode != 0 && last_followup == PIPE_AND)
8343 /* It is "<true> || CMD" or "<false> && CMD"
8344 * and we should not execute CMD */
8345 debug_printf_exec("skipped cmd because of || or &&\n");
8346 last_followup = pi->followup;
8347 goto dont_check_jobs_but_continue;
8350 last_followup = pi->followup;
8351 IF_HAS_KEYWORDS(last_rword = rword;)
8354 if (rword == RES_THEN) {
8355 /* if false; then ... fi has exitcode 0! */
8356 G.last_exitcode = rcode = EXIT_SUCCESS;
8357 /* "if <false> THEN cmd": skip cmd */
8361 if (rword == RES_ELSE || rword == RES_ELIF) {
8362 /* "if <true> then ... ELSE/ELIF cmd":
8363 * skip cmd and all following ones */
8368 #if ENABLE_HUSH_LOOPS
8369 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8371 /* first loop through for */
8373 static const char encoded_dollar_at[] ALIGN1 = {
8374 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8375 }; /* encoded representation of "$@" */
8376 static const char *const encoded_dollar_at_argv[] = {
8377 encoded_dollar_at, NULL
8378 }; /* argv list with one element: "$@" */
8381 vals = (char**)encoded_dollar_at_argv;
8382 if (pi->next->res_word == RES_IN) {
8383 /* if no variable values after "in" we skip "for" */
8384 if (!pi->next->cmds[0].argv) {
8385 G.last_exitcode = rcode = EXIT_SUCCESS;
8386 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8389 vals = pi->next->cmds[0].argv;
8390 } /* else: "for var; do..." -> assume "$@" list */
8391 /* create list of variable values */
8392 debug_print_strings("for_list made from", vals);
8393 for_list = expand_strvec_to_strvec(vals);
8394 for_lcur = for_list;
8395 debug_print_strings("for_list", for_list);
8398 /* "for" loop is over, clean up */
8404 /* Insert next value from for_lcur */
8405 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8406 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8409 if (rword == RES_IN) {
8410 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8412 if (rword == RES_DONE) {
8413 continue; /* "done" has no cmds too */
8416 #if ENABLE_HUSH_CASE
8417 if (rword == RES_CASE) {
8418 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8419 case_word = expand_strvec_to_string(pi->cmds->argv);
8420 unbackslash(case_word);
8423 if (rword == RES_MATCH) {
8426 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8427 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8429 /* all prev words didn't match, does this one match? */
8430 argv = pi->cmds->argv;
8432 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8433 /* TODO: which FNM_xxx flags to use? */
8434 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8435 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8437 if (cond_code == 0) { /* match! we will execute this branch */
8439 case_word = NULL; /* make future "word)" stop */
8446 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8447 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8449 continue; /* not matched yet, skip this pipe */
8451 if (rword == RES_ESAC) {
8452 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8454 /* "case" did not match anything: still set $? (to 0) */
8455 G.last_exitcode = rcode = EXIT_SUCCESS;
8459 /* Just pressing <enter> in shell should check for jobs.
8460 * OTOH, in non-interactive shell this is useless
8461 * and only leads to extra job checks */
8462 if (pi->num_cmds == 0) {
8463 if (G_interactive_fd)
8464 goto check_jobs_and_continue;
8468 /* After analyzing all keywords and conditions, we decided
8469 * to execute this pipe. NB: have to do checkjobs(NULL)
8470 * after run_pipe to collect any background children,
8471 * even if list execution is to be stopped. */
8472 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8473 #if ENABLE_HUSH_LOOPS
8474 G.flag_break_continue = 0;
8476 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8478 /* We ran a builtin, function, or group.
8479 * rcode is already known
8480 * and we don't need to wait for anything. */
8481 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8482 G.last_exitcode = rcode;
8483 check_and_run_traps();
8484 #if ENABLE_HUSH_LOOPS
8485 /* Was it "break" or "continue"? */
8486 if (G.flag_break_continue) {
8487 smallint fbc = G.flag_break_continue;
8488 /* We might fall into outer *loop*,
8489 * don't want to break it too */
8491 G.depth_break_continue--;
8492 if (G.depth_break_continue == 0)
8493 G.flag_break_continue = 0;
8494 /* else: e.g. "continue 2" should *break* once, *then* continue */
8495 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8496 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8497 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8500 /* "continue": simulate end of loop */
8505 if (G_flag_return_in_progress == 1) {
8506 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8509 } else if (pi->followup == PIPE_BG) {
8510 /* What does bash do with attempts to background builtins? */
8511 /* even bash 3.2 doesn't do that well with nested bg:
8512 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8513 * I'm NOT treating inner &'s as jobs */
8515 if (G.run_list_level == 1)
8516 insert_job_into_table(pi);
8518 /* Last command's pid goes to $! */
8519 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8520 G.last_bg_pid_exitcode = 0;
8521 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8522 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
8523 rcode = EXIT_SUCCESS;
8527 if (G.run_list_level == 1 && G_interactive_fd) {
8528 /* Waits for completion, then fg's main shell */
8529 rcode = checkjobs_and_fg_shell(pi);
8530 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8534 /* This one just waits for completion */
8535 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8536 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8538 G.last_exitcode = rcode;
8539 check_and_run_traps();
8542 /* Handle "set -e" */
8543 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8544 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8545 if (G.errexit_depth == 0)
8548 G.errexit_depth = sv_errexit_depth;
8550 /* Analyze how result affects subsequent commands */
8552 if (rword == RES_IF || rword == RES_ELIF)
8555 check_jobs_and_continue:
8556 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8557 dont_check_jobs_but_continue: ;
8558 #if ENABLE_HUSH_LOOPS
8559 /* Beware of "while false; true; do ..."! */
8561 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8562 /* check for RES_DONE is needed for "while ...; do \n done" case */
8564 if (rword == RES_WHILE) {
8566 /* "while false; do...done" - exitcode 0 */
8567 G.last_exitcode = rcode = EXIT_SUCCESS;
8568 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8572 if (rword == RES_UNTIL) {
8574 debug_printf_exec(": until expr is true: breaking\n");
8585 #if ENABLE_HUSH_LOOPS
8590 #if ENABLE_HUSH_CASE
8594 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8598 /* Select which version we will use */
8599 static int run_and_free_list(struct pipe *pi)
8602 debug_printf_exec("run_and_free_list entered\n");
8603 if (!G.o_opt[OPT_O_NOEXEC]) {
8604 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8605 rcode = run_list(pi);
8607 /* free_pipe_list has the side effect of clearing memory.
8608 * In the long run that function can be merged with run_list,
8609 * but doing that now would hobble the debugging effort. */
8611 debug_printf_exec("run_and_free_list return %d\n", rcode);
8616 static void install_sighandlers(unsigned mask)
8618 sighandler_t old_handler;
8620 while ((mask >>= 1) != 0) {
8624 old_handler = install_sighandler(sig, pick_sighandler(sig));
8625 /* POSIX allows shell to re-enable SIGCHLD
8626 * even if it was SIG_IGN on entry.
8627 * Therefore we skip IGN check for it:
8631 if (old_handler == SIG_IGN) {
8632 /* oops... restore back to IGN, and record this fact */
8633 install_sighandler(sig, old_handler);
8634 #if ENABLE_HUSH_TRAP
8636 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8638 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8644 /* Called a few times only (or even once if "sh -c") */
8645 static void install_special_sighandlers(void)
8649 /* Which signals are shell-special? */
8650 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8651 if (G_interactive_fd) {
8652 mask |= SPECIAL_INTERACTIVE_SIGS;
8653 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8654 mask |= SPECIAL_JOBSTOP_SIGS;
8656 /* Careful, do not re-install handlers we already installed */
8657 if (G.special_sig_mask != mask) {
8658 unsigned diff = mask & ~G.special_sig_mask;
8659 G.special_sig_mask = mask;
8660 install_sighandlers(diff);
8666 /* Set handlers to restore tty pgrp and exit */
8667 static void install_fatal_sighandlers(void)
8671 /* We will restore tty pgrp on these signals */
8673 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8674 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8675 + (1 << SIGBUS ) * HUSH_DEBUG
8676 + (1 << SIGSEGV) * HUSH_DEBUG
8677 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8679 /* bash 3.2 seems to handle these just like 'fatal' ones */
8682 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8683 * if we aren't interactive... but in this case
8684 * we never want to restore pgrp on exit, and this fn is not called
8686 /*+ (1 << SIGHUP )*/
8687 /*+ (1 << SIGTERM)*/
8688 /*+ (1 << SIGINT )*/
8690 G_fatal_sig_mask = mask;
8692 install_sighandlers(mask);
8696 static int set_mode(int state, char mode, const char *o_opt)
8701 G.o_opt[OPT_O_NOEXEC] = state;
8704 IF_HUSH_MODE_X(G_x_mode = state;)
8708 /* "set -+o" without parameter.
8709 * in bash, set -o produces this output:
8713 * We always use the second form.
8715 const char *p = o_opt_strings;
8718 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8724 idx = index_in_strings(o_opt_strings, o_opt);
8726 G.o_opt[idx] = state;
8730 G.o_opt[OPT_O_ERREXIT] = state;
8733 return EXIT_FAILURE;
8735 return EXIT_SUCCESS;
8738 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8739 int hush_main(int argc, char **argv)
8742 OPT_login = (1 << 0),
8746 unsigned builtin_argc;
8748 struct variable *cur_var;
8749 struct variable *shell_ver;
8752 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8753 G.last_exitcode = EXIT_SUCCESS;
8755 #if ENABLE_HUSH_FAST
8756 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8759 G.argv0_for_re_execing = argv[0];
8761 /* Deal with HUSH_VERSION */
8762 shell_ver = xzalloc(sizeof(*shell_ver));
8763 shell_ver->flg_export = 1;
8764 shell_ver->flg_read_only = 1;
8765 /* Code which handles ${var<op>...} needs writable values for all variables,
8766 * therefore we xstrdup: */
8767 shell_ver->varstr = xstrdup(hush_version_str);
8768 /* Create shell local variables from the values
8769 * currently living in the environment */
8770 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8771 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8772 G.top_var = shell_ver;
8773 cur_var = G.top_var;
8776 char *value = strchr(*e, '=');
8777 if (value) { /* paranoia */
8778 cur_var->next = xzalloc(sizeof(*cur_var));
8779 cur_var = cur_var->next;
8780 cur_var->varstr = *e;
8781 cur_var->max_len = strlen(*e);
8782 cur_var->flg_export = 1;
8786 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8787 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8788 putenv(shell_ver->varstr);
8791 set_pwd_var(SETFLAG_EXPORT);
8793 #if BASH_HOSTNAME_VAR
8794 /* Set (but not export) HOSTNAME unless already set */
8795 if (!get_local_var_value("HOSTNAME")) {
8798 set_local_var_from_halves("HOSTNAME", uts.nodename);
8800 /* bash also exports SHLVL and _,
8801 * and sets (but doesn't export) the following variables:
8803 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8804 * BASH_VERSION='3.2.0(1)-release'
8806 * MACHTYPE=i386-pc-linux-gnu
8808 * PPID=<NNNNN> - we also do it elsewhere
8819 * PIPESTATUS=([0]="0")
8820 * HISTFILE=/<xxx>/.bash_history
8824 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8826 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8837 #if ENABLE_FEATURE_EDITING
8838 G.line_input_state = new_line_input_t(FOR_SHELL);
8841 /* Initialize some more globals to non-zero values */
8842 cmdedit_update_prompt();
8844 die_func = restore_ttypgrp_and__exit;
8846 /* Shell is non-interactive at first. We need to call
8847 * install_special_sighandlers() if we are going to execute "sh <script>",
8848 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8849 * If we later decide that we are interactive, we run install_special_sighandlers()
8850 * in order to intercept (more) signals.
8854 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8855 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8858 opt = getopt(argc, argv, "+c:exinsl"
8861 # if ENABLE_HUSH_FUNCTIONS
8871 * sh ... -c 'script'
8872 * sh ... -c 'script' ARG0 [ARG1...]
8873 * On NOMMU, if builtin_argc != 0,
8874 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8875 * "" needs to be replaced with NULL
8876 * and BARGV vector fed to builtin function.
8877 * Note: the form without ARG0 never happens:
8878 * sh ... -c 'builtin' BARGV... ""
8881 G.root_pid = getpid();
8882 G.root_ppid = getppid();
8884 G.global_argv = argv + optind;
8885 G.global_argc = argc - optind;
8887 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8888 const struct built_in_command *x;
8890 install_special_sighandlers();
8891 x = find_builtin(optarg);
8892 if (x) { /* paranoia */
8893 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8894 G.global_argv += builtin_argc;
8895 G.global_argv[-1] = NULL; /* replace "" */
8897 G.last_exitcode = x->b_function(argv + optind - 1);
8901 if (!G.global_argv[0]) {
8902 /* -c 'script' (no params): prevent empty $0 */
8903 G.global_argv--; /* points to argv[i] of 'script' */
8904 G.global_argv[0] = argv[0];
8906 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8907 install_special_sighandlers();
8908 parse_and_run_string(optarg);
8911 /* Well, we cannot just declare interactiveness,
8912 * we have to have some stuff (ctty, etc) */
8913 /* G_interactive_fd++; */
8916 /* "-s" means "read from stdin", but this is how we always
8917 * operate, so simply do nothing here. */
8923 case '<': /* "big heredoc" support */
8924 full_write1_str(optarg);
8927 unsigned long long empty_trap_mask;
8929 G.root_pid = bb_strtou(optarg, &optarg, 16);
8931 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8933 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8935 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8937 builtin_argc = bb_strtou(optarg, &optarg, 16);
8939 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8940 if (empty_trap_mask != 0) {
8941 IF_HUSH_TRAP(int sig;)
8942 install_special_sighandlers();
8943 # if ENABLE_HUSH_TRAP
8944 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8945 for (sig = 1; sig < NSIG; sig++) {
8946 if (empty_trap_mask & (1LL << sig)) {
8947 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8948 install_sighandler(sig, SIG_IGN);
8953 # if ENABLE_HUSH_LOOPS
8955 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8961 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
8963 # if ENABLE_HUSH_FUNCTIONS
8965 struct function *funcp = new_function(optarg);
8966 /* funcp->name is already set to optarg */
8967 /* funcp->body is set to NULL. It's a special case. */
8968 funcp->body_as_string = argv[optind];
8977 if (set_mode(1, opt, NULL) == 0) /* no error */
8981 fprintf(stderr, "Usage: sh [FILE]...\n"
8982 " or: sh -c command [args]...\n\n");
8988 } /* option parsing loop */
8990 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8991 G.global_argc = argc - (optind - 1);
8992 G.global_argv = argv + (optind - 1);
8993 G.global_argv[0] = argv[0];
8996 G.root_pid = getpid();
8997 G.root_ppid = getppid();
9000 /* If we are login shell... */
9001 if (flags & OPT_login) {
9003 debug_printf("sourcing /etc/profile\n");
9004 input = fopen_for_read("/etc/profile");
9005 if (input != NULL) {
9006 remember_FILE(input);
9007 install_special_sighandlers();
9008 parse_and_run_file(input);
9009 fclose_and_forget(input);
9011 /* bash: after sourcing /etc/profile,
9012 * tries to source (in the given order):
9013 * ~/.bash_profile, ~/.bash_login, ~/.profile,
9014 * stopping on first found. --noprofile turns this off.
9015 * bash also sources ~/.bash_logout on exit.
9016 * If called as sh, skips .bash_XXX files.
9020 if (G.global_argv[1]) {
9023 * "bash <script>" (which is never interactive (unless -i?))
9024 * sources $BASH_ENV here (without scanning $PATH).
9025 * If called as sh, does the same but with $ENV.
9026 * Also NB, per POSIX, $ENV should undergo parameter expansion.
9030 debug_printf("running script '%s'\n", G.global_argv[0]);
9031 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
9032 input = xfopen_for_read(G.global_argv[0]);
9033 xfunc_error_retval = 1;
9034 remember_FILE(input);
9035 install_special_sighandlers();
9036 parse_and_run_file(input);
9037 #if ENABLE_FEATURE_CLEAN_UP
9038 fclose_and_forget(input);
9043 /* Up to here, shell was non-interactive. Now it may become one.
9044 * NB: don't forget to (re)run install_special_sighandlers() as needed.
9047 /* A shell is interactive if the '-i' flag was given,
9048 * or if all of the following conditions are met:
9050 * no arguments remaining or the -s flag given
9051 * standard input is a terminal
9052 * standard output is a terminal
9053 * Refer to Posix.2, the description of the 'sh' utility.
9056 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9057 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
9058 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
9059 if (G_saved_tty_pgrp < 0)
9060 G_saved_tty_pgrp = 0;
9062 /* try to dup stdin to high fd#, >= 255 */
9063 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9064 if (G_interactive_fd < 0) {
9065 /* try to dup to any fd */
9066 G_interactive_fd = dup(STDIN_FILENO);
9067 if (G_interactive_fd < 0) {
9069 G_interactive_fd = 0;
9070 G_saved_tty_pgrp = 0;
9073 // TODO: track & disallow any attempts of user
9074 // to (inadvertently) close/redirect G_interactive_fd
9076 debug_printf("interactive_fd:%d\n", G_interactive_fd);
9077 if (G_interactive_fd) {
9078 close_on_exec_on(G_interactive_fd);
9080 if (G_saved_tty_pgrp) {
9081 /* If we were run as 'hush &', sleep until we are
9082 * in the foreground (tty pgrp == our pgrp).
9083 * If we get started under a job aware app (like bash),
9084 * make sure we are now in charge so we don't fight over
9085 * who gets the foreground */
9087 pid_t shell_pgrp = getpgrp();
9088 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
9089 if (G_saved_tty_pgrp == shell_pgrp)
9091 /* send TTIN to ourself (should stop us) */
9092 kill(- shell_pgrp, SIGTTIN);
9096 /* Install more signal handlers */
9097 install_special_sighandlers();
9099 if (G_saved_tty_pgrp) {
9100 /* Set other signals to restore saved_tty_pgrp */
9101 install_fatal_sighandlers();
9102 /* Put ourselves in our own process group
9103 * (bash, too, does this only if ctty is available) */
9104 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
9105 /* Grab control of the terminal */
9106 tcsetpgrp(G_interactive_fd, getpid());
9108 enable_restore_tty_pgrp_on_exit();
9110 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
9112 const char *hp = get_local_var_value("HISTFILE");
9114 hp = get_local_var_value("HOME");
9116 hp = concat_path_file(hp, ".hush_history");
9121 G.line_input_state->hist_file = hp;
9122 //set_local_var(xasprintf("HISTFILE=%s", ...));
9124 # if ENABLE_FEATURE_SH_HISTFILESIZE
9125 hp = get_local_var_value("HISTFILESIZE");
9126 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
9131 install_special_sighandlers();
9133 #elif ENABLE_HUSH_INTERACTIVE
9134 /* No job control compiled in, only prompt/line editing */
9135 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9136 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9137 if (G_interactive_fd < 0) {
9138 /* try to dup to any fd */
9139 G_interactive_fd = dup(STDIN_FILENO);
9140 if (G_interactive_fd < 0)
9142 G_interactive_fd = 0;
9145 if (G_interactive_fd) {
9146 close_on_exec_on(G_interactive_fd);
9148 install_special_sighandlers();
9150 /* We have interactiveness code disabled */
9151 install_special_sighandlers();
9154 * if interactive but not a login shell, sources ~/.bashrc
9155 * (--norc turns this off, --rcfile <file> overrides)
9158 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9159 /* note: ash and hush share this string */
9160 printf("\n\n%s %s\n"
9161 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9164 "hush - the humble shell"
9168 parse_and_run_file(stdin);
9171 hush_exit(G.last_exitcode);
9178 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9183 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9184 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9186 int argc = string_array_len(argv);
9187 return applet_main_func(argc, argv);
9190 #if ENABLE_HUSH_TEST || BASH_TEST2
9191 static int FAST_FUNC builtin_test(char **argv)
9193 return run_applet_main(argv, test_main);
9196 #if ENABLE_HUSH_ECHO
9197 static int FAST_FUNC builtin_echo(char **argv)
9199 return run_applet_main(argv, echo_main);
9202 #if ENABLE_HUSH_PRINTF
9203 static int FAST_FUNC builtin_printf(char **argv)
9205 return run_applet_main(argv, printf_main);
9209 #if ENABLE_HUSH_HELP
9210 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9212 const struct built_in_command *x;
9215 "Built-in commands:\n"
9216 "------------------\n");
9217 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9219 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9221 return EXIT_SUCCESS;
9225 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9226 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9228 show_history(G.line_input_state);
9229 return EXIT_SUCCESS;
9233 static char **skip_dash_dash(char **argv)
9236 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9241 static int FAST_FUNC builtin_cd(char **argv)
9245 argv = skip_dash_dash(argv);
9247 if (newdir == NULL) {
9248 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9249 * bash says "bash: cd: HOME not set" and does nothing
9252 const char *home = get_local_var_value("HOME");
9253 newdir = home ? home : "/";
9255 if (chdir(newdir)) {
9256 /* Mimic bash message exactly */
9257 bb_perror_msg("cd: %s", newdir);
9258 return EXIT_FAILURE;
9260 /* Read current dir (get_cwd(1) is inside) and set PWD.
9261 * Note: do not enforce exporting. If PWD was unset or unexported,
9262 * set it again, but do not export. bash does the same.
9264 set_pwd_var(/*flag:*/ 0);
9265 return EXIT_SUCCESS;
9268 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9271 return EXIT_SUCCESS;
9274 static int FAST_FUNC builtin_eval(char **argv)
9276 int rcode = EXIT_SUCCESS;
9278 argv = skip_dash_dash(argv);
9280 char *str = expand_strvec_to_string(argv);
9282 * eval "echo Hi; done" ("done" is syntax error):
9283 * "echo Hi" will not execute too.
9285 parse_and_run_string(str);
9287 rcode = G.last_exitcode;
9292 static int FAST_FUNC builtin_exec(char **argv)
9294 argv = skip_dash_dash(argv);
9295 if (argv[0] == NULL)
9296 return EXIT_SUCCESS; /* bash does this */
9298 /* Careful: we can end up here after [v]fork. Do not restore
9299 * tty pgrp then, only top-level shell process does that */
9300 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9301 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9303 /* Saved-redirect fds, script fds and G_interactive_fd are still
9304 * open here. However, they are all CLOEXEC, and execv below
9305 * closes them. Try interactive "exec ls -l /proc/self/fd",
9306 * it should show no extra open fds in the "ls" process.
9307 * If we'd try to run builtins/NOEXECs, this would need improving.
9309 //close_saved_fds_and_FILE_fds();
9311 /* TODO: if exec fails, bash does NOT exit! We do.
9312 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9313 * and tcsetpgrp, and this is inherently racy.
9315 execvp_or_die(argv);
9318 static int FAST_FUNC builtin_exit(char **argv)
9320 debug_printf_exec("%s()\n", __func__);
9322 /* interactive bash:
9323 * # trap "echo EEE" EXIT
9326 * There are stopped jobs.
9327 * (if there are _stopped_ jobs, running ones don't count)
9330 * EEE (then bash exits)
9332 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9335 /* note: EXIT trap is run by hush_exit */
9336 argv = skip_dash_dash(argv);
9337 if (argv[0] == NULL)
9338 hush_exit(G.last_exitcode);
9339 /* mimic bash: exit 123abc == exit 255 + error msg */
9340 xfunc_error_retval = 255;
9341 /* bash: exit -2 == exit 254, no error msg */
9342 hush_exit(xatoi(argv[0]) & 0xff);
9345 #if ENABLE_HUSH_TYPE
9346 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9347 static int FAST_FUNC builtin_type(char **argv)
9349 int ret = EXIT_SUCCESS;
9355 if (0) {} /* make conditional compile easier below */
9356 /*else if (find_alias(*argv))
9357 type = "an alias";*/
9358 #if ENABLE_HUSH_FUNCTIONS
9359 else if (find_function(*argv))
9360 type = "a function";
9362 else if (find_builtin(*argv))
9363 type = "a shell builtin";
9364 else if ((path = find_in_path(*argv)) != NULL)
9367 bb_error_msg("type: %s: not found", *argv);
9372 printf("%s is %s\n", *argv, type);
9380 #if ENABLE_HUSH_READ
9381 /* Interruptibility of read builtin in bash
9382 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9384 * Empty trap makes read ignore corresponding signal, for any signal.
9387 * - terminates non-interactive shell;
9388 * - interrupts read in interactive shell;
9389 * if it has non-empty trap:
9390 * - executes trap and returns to command prompt in interactive shell;
9391 * - executes trap and returns to read in non-interactive shell;
9393 * - is ignored (does not interrupt) read in interactive shell;
9394 * - terminates non-interactive shell;
9395 * if it has non-empty trap:
9396 * - executes trap and returns to read;
9398 * - terminates shell (regardless of interactivity);
9399 * if it has non-empty trap:
9400 * - executes trap and returns to read;
9401 * SIGCHLD from children:
9402 * - does not interrupt read regardless of interactivity:
9403 * try: sleep 1 & read x; echo $x
9405 static int FAST_FUNC builtin_read(char **argv)
9415 /* "!": do not abort on errors.
9416 * Option string must start with "sr" to match BUILTIN_READ_xxx
9418 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9419 if (read_flags == (uint32_t)-1)
9420 return EXIT_FAILURE;
9422 ifs = get_local_var_value("IFS"); /* can be NULL */
9425 r = shell_builtin_read(set_local_var_from_halves,
9435 if ((uintptr_t)r == 1 && errno == EINTR) {
9436 unsigned sig = check_and_run_traps();
9441 if ((uintptr_t)r > 1) {
9442 bb_error_msg("%s", r);
9443 r = (char*)(uintptr_t)1;
9446 return (uintptr_t)r;
9450 #if ENABLE_HUSH_UMASK
9451 static int FAST_FUNC builtin_umask(char **argv)
9458 argv = skip_dash_dash(argv);
9460 mode_t old_mask = mask;
9462 /* numeric umasks are taken as-is */
9463 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9464 if (!isdigit(argv[0][0]))
9466 mask = bb_parse_mode(argv[0], mask);
9467 if (!isdigit(argv[0][0]))
9469 if ((unsigned)mask > 0777) {
9472 * bash: umask: 'q': invalid symbolic mode operator
9473 * bash: umask: 999: octal number out of range
9475 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9480 printf("%04o\n", (unsigned) mask);
9481 /* fall through and restore mask which we set to 0 */
9485 return !rc; /* rc != 0 - success */
9489 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9490 static void print_escaped(const char *s)
9495 const char *p = strchrnul(s, '\'');
9496 /* print 'xxxx', possibly just '' */
9497 printf("'%.*s'", (int)(p - s), s);
9502 /* s points to '; print "'''...'''" */
9504 do putchar('\''); while (*++s == '\'');
9510 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9511 static int helper_export_local(char **argv, unsigned flags)
9515 char *name_end = strchrnul(name, '=');
9517 /* So far we do not check that name is valid (TODO?) */
9519 if (*name_end == '\0') {
9520 struct variable *var, **vpp;
9522 vpp = get_ptr_to_local_var(name, name_end - name);
9523 var = vpp ? *vpp : NULL;
9525 if (flags & SETFLAG_UNEXPORT) {
9526 /* export -n NAME (without =VALUE) */
9528 var->flg_export = 0;
9529 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9531 } /* else: export -n NOT_EXISTING_VAR: no-op */
9534 if (flags & SETFLAG_EXPORT) {
9535 /* export NAME (without =VALUE) */
9537 var->flg_export = 1;
9538 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9539 putenv(var->varstr);
9543 if (flags & SETFLAG_MAKE_RO) {
9544 /* readonly NAME (without =VALUE) */
9546 var->flg_read_only = 1;
9550 # if ENABLE_HUSH_LOCAL
9551 /* Is this "local" bltin? */
9552 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9553 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9554 if (var && var->func_nest_level == lvl) {
9555 /* "local x=abc; ...; local x" - ignore second local decl */
9560 /* Exporting non-existing variable.
9561 * bash does not put it in environment,
9562 * but remembers that it is exported,
9563 * and does put it in env when it is set later.
9564 * We just set it to "" and export.
9566 /* Or, it's "local NAME" (without =VALUE).
9567 * bash sets the value to "".
9569 /* Or, it's "readonly NAME" (without =VALUE).
9570 * bash remembers NAME and disallows its creation
9573 name = xasprintf("%s=", name);
9575 /* (Un)exporting/making local NAME=VALUE */
9576 name = xstrdup(name);
9578 if (set_local_var(name, flags))
9579 return EXIT_FAILURE;
9581 return EXIT_SUCCESS;
9585 #if ENABLE_HUSH_EXPORT
9586 static int FAST_FUNC builtin_export(char **argv)
9588 unsigned opt_unexport;
9590 #if ENABLE_HUSH_EXPORT_N
9591 /* "!": do not abort on errors */
9592 opt_unexport = getopt32(argv, "!n");
9593 if (opt_unexport == (uint32_t)-1)
9594 return EXIT_FAILURE;
9601 if (argv[0] == NULL) {
9608 /* ash emits: export VAR='VAL'
9609 * bash: declare -x VAR="VAL"
9610 * we follow ash example */
9611 const char *s = *e++;
9612 const char *p = strchr(s, '=');
9614 if (!p) /* wtf? take next variable */
9617 printf("export %.*s", (int)(p - s) + 1, s);
9618 print_escaped(p + 1);
9622 /*fflush_all(); - done after each builtin anyway */
9624 return EXIT_SUCCESS;
9627 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9631 #if ENABLE_HUSH_LOCAL
9632 static int FAST_FUNC builtin_local(char **argv)
9634 if (G.func_nest_level == 0) {
9635 bb_error_msg("%s: not in a function", argv[0]);
9636 return EXIT_FAILURE; /* bash compat */
9639 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9643 #if ENABLE_HUSH_READONLY
9644 static int FAST_FUNC builtin_readonly(char **argv)
9647 if (*argv == NULL) {
9648 /* bash: readonly [-p]: list all readonly VARs
9649 * (-p has no effect in bash)
9652 for (e = G.top_var; e; e = e->next) {
9653 if (e->flg_read_only) {
9654 //TODO: quote value: readonly VAR='VAL'
9655 printf("readonly %s\n", e->varstr);
9658 return EXIT_SUCCESS;
9660 return helper_export_local(argv, SETFLAG_MAKE_RO);
9664 #if ENABLE_HUSH_UNSET
9665 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9666 static int FAST_FUNC builtin_unset(char **argv)
9671 /* "!": do not abort on errors */
9672 /* "+": stop at 1st non-option */
9673 opts = getopt32(argv, "!+vf");
9674 if (opts == (unsigned)-1)
9675 return EXIT_FAILURE;
9677 bb_error_msg("unset: -v and -f are exclusive");
9678 return EXIT_FAILURE;
9684 if (!(opts & 2)) { /* not -f */
9685 if (unset_local_var(*argv)) {
9686 /* unset <nonexistent_var> doesn't fail.
9687 * Error is when one tries to unset RO var.
9688 * Message was printed by unset_local_var. */
9692 # if ENABLE_HUSH_FUNCTIONS
9704 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9705 * built-in 'set' handler
9707 * set [-abCefhmnuvx] [-o option] [argument...]
9708 * set [+abCefhmnuvx] [+o option] [argument...]
9709 * set -- [argument...]
9712 * Implementations shall support the options in both their hyphen and
9713 * plus-sign forms. These options can also be specified as options to sh.
9715 * Write out all variables and their values: set
9716 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9717 * Turn on the -x and -v options: set -xv
9718 * Unset all positional parameters: set --
9719 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9720 * Set the positional parameters to the expansion of x, even if x expands
9721 * with a leading '-' or '+': set -- $x
9723 * So far, we only support "set -- [argument...]" and some of the short names.
9725 static int FAST_FUNC builtin_set(char **argv)
9728 char **pp, **g_argv;
9729 char *arg = *++argv;
9733 for (e = G.top_var; e; e = e->next)
9735 return EXIT_SUCCESS;
9739 if (strcmp(arg, "--") == 0) {
9743 if (arg[0] != '+' && arg[0] != '-')
9745 for (n = 1; arg[n]; ++n) {
9746 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9748 if (arg[n] == 'o' && argv[1])
9751 } while ((arg = *++argv) != NULL);
9752 /* Now argv[0] is 1st argument */
9755 return EXIT_SUCCESS;
9758 /* NB: G.global_argv[0] ($0) is never freed/changed */
9759 g_argv = G.global_argv;
9760 if (G.global_args_malloced) {
9766 G.global_args_malloced = 1;
9767 pp = xzalloc(sizeof(pp[0]) * 2);
9768 pp[0] = g_argv[0]; /* retain $0 */
9771 /* This realloc's G.global_argv */
9772 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9774 G.global_argc = 1 + string_array_len(pp + 1);
9776 return EXIT_SUCCESS;
9778 /* Nothing known, so abort */
9780 bb_error_msg("set: %s: invalid option", arg);
9781 return EXIT_FAILURE;
9785 static int FAST_FUNC builtin_shift(char **argv)
9788 argv = skip_dash_dash(argv);
9790 n = bb_strtou(argv[0], NULL, 10);
9791 if (errno || n < 0) {
9792 /* shared string with ash.c */
9793 bb_error_msg("Illegal number: %s", argv[0]);
9795 * ash aborts in this case.
9796 * bash prints error message and set $? to 1.
9797 * Interestingly, for "shift 99999" bash does not
9798 * print error message, but does set $? to 1
9799 * (and does no shifting at all).
9803 if (n >= 0 && n < G.global_argc) {
9804 if (G_global_args_malloced) {
9807 free(G.global_argv[m++]);
9810 memmove(&G.global_argv[1], &G.global_argv[n+1],
9811 G.global_argc * sizeof(G.global_argv[0]));
9812 return EXIT_SUCCESS;
9814 return EXIT_FAILURE;
9817 static int FAST_FUNC builtin_source(char **argv)
9819 char *arg_path, *filename;
9822 char *args_need_save;
9823 #if ENABLE_HUSH_FUNCTIONS
9827 argv = skip_dash_dash(argv);
9830 /* bash says: "bash: .: filename argument required" */
9831 return 2; /* bash compat */
9834 if (!strchr(filename, '/')) {
9835 arg_path = find_in_path(filename);
9837 filename = arg_path;
9839 input = remember_FILE(fopen_or_warn(filename, "r"));
9842 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9843 /* POSIX: non-interactive shell should abort here,
9844 * not merely fail. So far no one complained :)
9846 return EXIT_FAILURE;
9849 #if ENABLE_HUSH_FUNCTIONS
9850 sv_flg = G_flag_return_in_progress;
9851 /* "we are inside sourced file, ok to use return" */
9852 G_flag_return_in_progress = -1;
9854 args_need_save = argv[1]; /* used as a boolean variable */
9856 save_and_replace_G_args(&sv, argv);
9858 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9859 G.last_exitcode = 0;
9860 parse_and_run_file(input);
9861 fclose_and_forget(input);
9863 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9864 restore_G_args(&sv, argv);
9865 #if ENABLE_HUSH_FUNCTIONS
9866 G_flag_return_in_progress = sv_flg;
9869 return G.last_exitcode;
9872 #if ENABLE_HUSH_TRAP
9873 static int FAST_FUNC builtin_trap(char **argv)
9879 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9884 /* No args: print all trapped */
9885 for (i = 0; i < NSIG; ++i) {
9888 print_escaped(G_traps[i]);
9889 /* note: bash adds "SIG", but only if invoked
9890 * as "bash". If called as "sh", or if set -o posix,
9891 * then it prints short signal names.
9892 * We are printing short names: */
9893 printf(" %s\n", get_signame(i));
9896 /*fflush_all(); - done after each builtin anyway */
9897 return EXIT_SUCCESS;
9901 /* If first arg is a number: reset all specified signals */
9902 sig = bb_strtou(*argv, NULL, 10);
9908 sighandler_t handler;
9910 sig = get_signum(*argv++);
9913 /* Mimic bash message exactly */
9914 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9919 G_traps[sig] = xstrdup(new_cmd);
9921 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9922 get_signame(sig), sig, G_traps[sig]);
9924 /* There is no signal for 0 (EXIT) */
9929 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9931 /* We are removing trap handler */
9932 handler = pick_sighandler(sig);
9933 install_sighandler(sig, handler);
9938 if (!argv[1]) { /* no second arg */
9939 bb_error_msg("trap: invalid arguments");
9940 return EXIT_FAILURE;
9943 /* First arg is "-": reset all specified to default */
9944 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9945 /* Everything else: set arg as signal handler
9946 * (includes "" case, which ignores signal) */
9947 if (argv[0][0] == '-') {
9948 if (argv[0][1] == '\0') { /* "-" */
9949 /* new_cmd remains NULL: "reset these sigs" */
9952 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9955 /* else: "-something", no special meaning */
9960 goto process_sig_list;
9965 static struct pipe *parse_jobspec(const char *str)
9970 if (sscanf(str, "%%%u", &jobnum) != 1) {
9972 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9974 bb_error_msg("bad argument '%s'", str);
9977 /* It is "%%", "%+" or "%" - current job */
9978 jobnum = G.last_jobid;
9980 bb_error_msg("no current job");
9984 for (pi = G.job_list; pi; pi = pi->next) {
9985 if (pi->jobid == jobnum) {
9989 bb_error_msg("%u: no such job", jobnum);
9993 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9996 const char *status_string;
9998 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9999 for (job = G.job_list; job; job = job->next) {
10000 if (job->alive_cmds == job->stopped_cmds)
10001 status_string = "Stopped";
10003 status_string = "Running";
10005 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
10008 clean_up_last_dead_job();
10010 return EXIT_SUCCESS;
10013 /* built-in 'fg' and 'bg' handler */
10014 static int FAST_FUNC builtin_fg_bg(char **argv)
10019 if (!G_interactive_fd)
10020 return EXIT_FAILURE;
10022 /* If they gave us no args, assume they want the last backgrounded task */
10024 for (pi = G.job_list; pi; pi = pi->next) {
10025 if (pi->jobid == G.last_jobid) {
10029 bb_error_msg("%s: no current job", argv[0]);
10030 return EXIT_FAILURE;
10033 pi = parse_jobspec(argv[1]);
10035 return EXIT_FAILURE;
10037 /* TODO: bash prints a string representation
10038 * of job being foregrounded (like "sleep 1 | cat") */
10039 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
10040 /* Put the job into the foreground. */
10041 tcsetpgrp(G_interactive_fd, pi->pgrp);
10044 /* Restart the processes in the job */
10045 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
10046 for (i = 0; i < pi->num_cmds; i++) {
10047 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
10049 pi->stopped_cmds = 0;
10051 i = kill(- pi->pgrp, SIGCONT);
10053 if (errno == ESRCH) {
10054 delete_finished_job(pi);
10055 return EXIT_SUCCESS;
10057 bb_perror_msg("kill (SIGCONT)");
10060 if (argv[0][0] == 'f') {
10061 remove_job_from_table(pi); /* FG job shouldn't be in job table */
10062 return checkjobs_and_fg_shell(pi);
10064 return EXIT_SUCCESS;
10068 #if ENABLE_HUSH_KILL
10069 static int FAST_FUNC builtin_kill(char **argv)
10073 # if ENABLE_HUSH_JOB
10074 if (argv[1] && strcmp(argv[1], "-l") != 0) {
10082 if (argv[i][0] != '%')
10085 * "kill %N" - job kill
10086 * Converting to pgrp / pid kill
10088 pi = parse_jobspec(argv[i]);
10090 /* Eat bad jobspec */
10094 argv[j - 1] = argv[j];
10101 * In jobs started under job control, we signal
10102 * entire process group by kill -PGRP_ID.
10103 * This happens, f.e., in interactive shell.
10105 * Otherwise, we signal each child via
10106 * kill PID1 PID2 PID3.
10108 * sh -c 'sleep 1|sleep 1 & kill %1'
10109 * sh -c 'true|sleep 2 & sleep 1; kill %1'
10110 * sh -c 'true|sleep 1 & sleep 2; kill %1'
10112 n = G_interactive_fd ? 1 : pi->num_cmds;
10113 dst = alloca(n * sizeof(int)*4);
10115 if (G_interactive_fd)
10116 dst += sprintf(dst, " -%u", (int)pi->pgrp);
10117 else for (j = 0; j < n; j++) {
10118 struct command *cmd = &pi->cmds[j];
10119 /* Skip exited members of the job */
10123 * kill_main has matching code to expect
10124 * leading space. Needed to not confuse
10125 * negative pids with "kill -SIGNAL_NO" syntax
10127 dst += sprintf(dst, " %u", (int)cmd->pid);
10130 } while (argv[++i]);
10134 if (argv[1] || ret == 0) {
10135 ret = run_applet_main(argv, kill_main);
10137 /* else: ret = 1, "kill %bad_jobspec" case */
10142 #if ENABLE_HUSH_WAIT
10143 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10144 #if !ENABLE_HUSH_JOB
10145 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10147 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10154 if (!sigisemptyset(&G.pending_set))
10157 /* waitpid is not interruptible by SA_RESTARTed
10158 * signals which we use. Thus, this ugly dance:
10161 /* Make sure possible SIGCHLD is stored in kernel's
10162 * pending signal mask before we call waitpid.
10163 * Or else we may race with SIGCHLD, lose it,
10164 * and get stuck in sigsuspend...
10166 sigfillset(&oldset); /* block all signals, remember old set */
10167 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10169 if (!sigisemptyset(&G.pending_set)) {
10170 /* Crap! we raced with some signal! */
10174 /*errno = 0; - checkjobs does this */
10175 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10176 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10177 debug_printf_exec("checkjobs:%d\n", ret);
10178 #if ENABLE_HUSH_JOB
10179 if (waitfor_pipe) {
10180 int rcode = job_exited_or_stopped(waitfor_pipe);
10181 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10184 sigprocmask(SIG_SETMASK, &oldset, NULL);
10189 /* if ECHILD, there are no children (ret is -1 or 0) */
10190 /* if ret == 0, no children changed state */
10191 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10192 if (errno == ECHILD || ret) {
10194 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10196 sigprocmask(SIG_SETMASK, &oldset, NULL);
10199 /* Wait for SIGCHLD or any other signal */
10200 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10201 /* Note: sigsuspend invokes signal handler */
10202 sigsuspend(&oldset);
10204 sigprocmask(SIG_SETMASK, &oldset, NULL);
10206 /* So, did we get a signal? */
10207 sig = check_and_run_traps();
10208 if (sig /*&& sig != SIGCHLD - always true */) {
10209 /* Do this for any (non-ignored) signal, not only for ^C */
10213 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10218 static int FAST_FUNC builtin_wait(char **argv)
10223 argv = skip_dash_dash(argv);
10224 if (argv[0] == NULL) {
10225 /* Don't care about wait results */
10226 /* Note 1: must wait until there are no more children */
10227 /* Note 2: must be interruptible */
10229 * $ sleep 3 & sleep 6 & wait
10230 * [1] 30934 sleep 3
10231 * [2] 30935 sleep 6
10234 * $ sleep 3 & sleep 6 & wait
10235 * [1] 30936 sleep 3
10236 * [2] 30937 sleep 6
10238 * ^C <-- after ~4 sec from keyboard
10241 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10245 pid_t pid = bb_strtou(*argv, NULL, 10);
10246 if (errno || pid <= 0) {
10247 #if ENABLE_HUSH_JOB
10248 if (argv[0][0] == '%') {
10249 struct pipe *wait_pipe;
10250 ret = 127; /* bash compat for bad jobspecs */
10251 wait_pipe = parse_jobspec(*argv);
10253 ret = job_exited_or_stopped(wait_pipe);
10255 ret = wait_for_child_or_signal(wait_pipe, 0);
10257 /* waiting on "last dead job" removes it */
10258 clean_up_last_dead_job();
10261 /* else: parse_jobspec() already emitted error msg */
10265 /* mimic bash message */
10266 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10267 ret = EXIT_FAILURE;
10268 continue; /* bash checks all argv[] */
10271 /* Do we have such child? */
10272 ret = waitpid(pid, &status, WNOHANG);
10276 if (errno == ECHILD) {
10277 if (pid == G.last_bg_pid) {
10278 /* "wait $!" but last bg task has already exited. Try:
10279 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10280 * In bash it prints exitcode 0, then 3.
10281 * In dash, it is 127.
10283 ret = G.last_bg_pid_exitcode;
10285 /* Example: "wait 1". mimic bash message */
10286 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10290 bb_perror_msg("wait %s", *argv);
10292 continue; /* bash checks all argv[] */
10295 /* Yes, and it still runs */
10296 ret = wait_for_child_or_signal(NULL, pid);
10298 /* Yes, and it just exited */
10299 process_wait_result(NULL, pid, status);
10300 ret = WEXITSTATUS(status);
10301 if (WIFSIGNALED(status))
10302 ret = 128 + WTERMSIG(status);
10310 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10311 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10314 def = bb_strtou(argv[1], NULL, 10);
10315 if (errno || def < def_min || argv[2]) {
10316 bb_error_msg("%s: bad arguments", argv[0]);
10324 #if ENABLE_HUSH_LOOPS
10325 static int FAST_FUNC builtin_break(char **argv)
10328 if (G.depth_of_loop == 0) {
10329 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10330 /* if we came from builtin_continue(), need to undo "= 1" */
10331 G.flag_break_continue = 0;
10332 return EXIT_SUCCESS; /* bash compat */
10334 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10336 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10337 if (depth == UINT_MAX)
10338 G.flag_break_continue = BC_BREAK;
10339 if (G.depth_of_loop < depth)
10340 G.depth_break_continue = G.depth_of_loop;
10342 return EXIT_SUCCESS;
10345 static int FAST_FUNC builtin_continue(char **argv)
10347 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10348 return builtin_break(argv);
10352 #if ENABLE_HUSH_FUNCTIONS
10353 static int FAST_FUNC builtin_return(char **argv)
10357 if (G_flag_return_in_progress != -1) {
10358 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10359 return EXIT_FAILURE; /* bash compat */
10362 G_flag_return_in_progress = 1;
10365 * out of range: wraps around at 256, does not error out
10366 * non-numeric param:
10367 * f() { false; return qwe; }; f; echo $?
10368 * bash: return: qwe: numeric argument required <== we do this
10369 * 255 <== we also do this
10371 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10376 #if ENABLE_HUSH_MEMLEAK
10377 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10382 # ifdef M_TRIM_THRESHOLD
10383 /* Optional. Reduces probability of false positives */
10386 /* Crude attempt to find where "free memory" starts,
10387 * sans fragmentation. */
10389 l = (unsigned long)p;
10392 if (l < (unsigned long)p) l = (unsigned long)p;
10398 struct mallinfo mi = mallinfo();
10399 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10400 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10404 if (!G.memleak_value)
10405 G.memleak_value = l;
10407 l -= G.memleak_value;
10414 /* Exitcode is "how many kilobytes we leaked since 1st call" */